"If I'm waffling just say so and we'll move on, because we talk about ourselves a lot," says Charlie Mullins.
But the millionaire British founder of boiler-repairer-and-tap-fixer to the stars Pimlico Plumbers has got a lot to talk about - and it's worth listening to.
The youthful 64-year-old sits in one of the low leather sofas in his office.
The walls are adorned with pictures of him and the great and the good at the private company's base near Lambeth Palace. Although the jacket's off, he's wearing the sharpest of suits, designer shirt and the royal blue company tie, complete with logo.
The combination of fine tailoring with a piece of uniform seems incongruous but it's part of the Mullins brand. Yet he denies he is inseparable from Pimlico Plumbers, the £35 million ($65m)-a-year business he founded almost 40 years ago.
"I disagree, I really do. I do the PR, sort out the building improvement, keep an eye on the day to day stuff," he says. "But I've got 12 family members working here and 350 staff. We all drink from the same teapot and that's important."
He certainly does do the PR. He's a regular on TV and radio, most recently Channel 4's How'd You Get So Rich?, and has even appeared on Question Time, dishing out what he describes as "common sense, but the problem is it ain't that common".
Question Time was the "most nervous I've ever been" Mullins admits.
"There were a couple of difficult people on with me, but I held my own. You've got to remember that a lot of these educated people on those shows; they can't do up their own shoe laces. I'm direct and say what I think."
He has a healthy disregard for airs and graces - an attitude that has served him well. Having dropped out of school at 15 - though he jokes it "should have been 14, I was wasting time" - he has set up an empire and earned an estimated £70m fortune.
Becoming a plumber was a dream since he was just 9. "I bunked off school and helped the local plumber. He had a car, a motorbike, nice house, clothes, holidays and loads of money," recalls Mullins. "He told me: 'Do an apprenticeship in plumbing and you'll never be out of work'."
That inspirational figure was right and Mullins' success has been recognised with an OBE and - until recently (but more of that later) - regular calls for advice from politicians, including a position advising David Cameron when he was Prime Minister.
But now it appears Mullins is mulling a role in politics himself. A strong Remainer, he's disappointed in the referendum's outcome, disillusioned by the failure of successive governments to embrace apprenticeships and generally disenchanted with politicians.
"I've always wanted to be a plumber but now, maybe an MP. I've always said no before but..." he trails off.
What could this self-made man bring to Westminster, just across the Thames from his base?
"Honesty," Mullins says. "There's just too many liars, too many promises not being kept, and people just not being truthful enough.
"If someone asks you a direct question, give them a direct answer. A lot of them in politics are just concerned about their own position," he says with a strong Cockney accent.
Mullins says he is "fully supportive" of the Conservatives and believes Theresa May is "doing a great job" but sighs: "She was Remainer who switched camps."
Brexit, he says, is the big question for business. "At the moment the economy is holding its own, but let's not kid ourselves - it hasn't kicked in yet."
Pimlico Plumbers has taken action to prepare for the downturn he expects, cutting prices and "getting more vans out there" in anticipation of taking work from struggling rivals.
Should a Brexit recession hit, he's not certain Britain will leave the EU.
"I'm still not totally convinced," he says. "If things got really bad [May] may not do what she has agreed to do. Why is she going to put us in a worse recession? There could be a U-turn. You've got to remember she was a Remainer."
When I was apprentice, you went to a posh house and there would be a sign saying 'tradesman round the back' and you'd be let in by a servant... Now they are there with open arms, and have a cup of tea waiting for you.
Mullins says he was a great admirer of Margaret Thatcher - he started the business in 1979, the year she became Prime Minister - a year before she gave her famous "the lady is not for turning" speech. Would he admire May if it turned out she was for turning?
"Undoubtedly, blimey yeah," says Mullins. "If it's the right road, let's go down it and benefit from it. If it's the wrong road then you can turn back anytime you want."
Despite his admiration for the current Conservative leader, he admits his stance on Brexit "hasn't exactly made me flavour of the month at Downing St". He is yet to meet May, despite having been to No 10 "every few months" before her tenure. "She's busy with Brexit," Mullins says, but adds that until very recently the Government had "pushed business aside".
Despite growing uncertainty about what leaving the EU might mean, he feels that his warnings were dismissed. "When I came up with it as Charlie the plumber they were looking at me as if to say: 'Don't be stupid'." He does not like being told by politicians, many of whom have never had a "real job", that he doesn't know about business.
Another major concern for Mullins is apprenticeships. If anyone is a poster boy for such a system, it's Mullins, but he thinks current plans are failing to meet needs. He "goes along" with the recently introduced Apprenticeship Levy "because I'm all for training - but it's not the way they should be dealing with it".
"I've had conversations with all of them," he says citing a long list of heavyweight politicians. "They are fully aware that this won't solve the problem. What is needed is a job allowance going to employers to make a full wage so they can train people with the skills the companies need."
He imagines that creating this sort of scheme will save more than it costs. "Every time a youngster gets nicked, first thing they say is: 'I ain't got a job'," he says. "All that crime and rehabilitation costs a fortune."
He relates an anecdote of a visit by senior politician who told him creating such an apprenticeship scheme "wasn't that simple".
"I mean, they're the Government! Why ain't it simple?" he asks.
And Mullins has no time for those who don't want to work and a benefits system he feels encourages this attitude. He says he has huge respect for the fabled Polish plumbers coming to the UK and supposedly taking jobs from natives.
"Without them the Olympics wouldn't have been built - people knock immigrants but they are bringing something to the economy, they are paying tax, they are not stopping people getting work.
Plumbing's a very personal thing - you're going into someone's home. We work with a lot of high class people who are very busy, politicians, judges, stars.
"There's all these other people drawing off the country rather than putting in. What is stopping people from getting a job is the benefits system. Let's buy a big telly, fags, booze and watch Jeremy Kyle. Why would we want to work if the state's giving us a few hundred quid a week?"
Maybe straight-talking Mullins could be ennobled in the way Lord Alan Sugar was and take a role as an apprenticeship and business czar?
"All I am getting at is how we can resolve youth unemployment and the skills shortage and it's simple: follow the system I am telling them," he counters, adding he's "not bothered" by the prospect of a peerage. The OBE certificate proudly hanging in his office suggests otherwise. "I'm open to offers; put it like that," Mullins smiles.
How did Pimlico Plumbers become the success is has?
It's simple, says Mullins: "You've got to do the best at what you do."
In his company's case, it's a combination skills, customer service, reliability, presentation and trust.
"Plumbing's a very personal thing - you're going into someone's home. We work with a lot of high-class people who are very busy: politicians, judges, stars," he says.
"They want someone they can trust and who will be honest with them - most of them don't have much idea about what we do so they like a plumber who can explain what's going on. There's a million plumbers out there but that's why we are successful."
From the company's reception, there's no doubt Pimlico Plumbers caters to London's rich and famous: the walls are covered with their signed photos. Asked how big a proportion of the client base is made up of the great and the good, Mullins guesses at 10 per cent, but then dials his call centre to find out for sure. He's shocked to be told that "high class people" are responsible for 60 per cent of his business.
Still reeling from the discovery, Mullins says his company has 8 per cent of the London market, but notes it's "really double that, because 50 per cent of the work we're not interested in". Then again, dialling through to the call centre could mean Pimlico Plumbers is cornering the market.
And he's hoping to get bigger, recession or not: "We want to go right to the outskirts of London and I'd be shocked if our turnover wasn't £100m in 10 years but I'd like to say we're aiming for five."
These are all big dreams for someone who left school with no qualifications - but looking at what Mullins has achieved it would foolish to dismiss them.
Especially for a man who says he's helped make plumbing "trendy" and change the image of the business.
"It's not looked down on now," he says. "When I was apprentice, you went to a posh house and there would be a sign saying 'tradesman round the back' and you'd be let in by a servant, you wouldn't even see people who own the property. Now they are there with open arms, and have a cup of tea waiting for you."