LONDON - Finding a good-looking commoner is easy enough. But a prince, that is much harder work.

Talent agencies in the UK are scrambling to find decent lookalikes for Prince William to keep up with the surge in demand in the lead-up to his April 29 wedding to Kate Middleton.

As for Kates, there may almost be an oversupply with one agency purporting to have 28 dead-ringers for the royal-in-waiting.

For those unfamiliar with lookalikes, talent agencies say in many instances they not only have to look the part but carry off the voice and mannerisms of their characters.

Amy Crumpton, of A-List Lookalikes, says that is the tough part when it to comes to replicating the second in line to the throne.

"I think it is because he has such a unique look," she says.

"It is also his mannerisms and how he speaks and they have to be able to do the voice as well."

She says the Leeds-based firm has one William on its books but dismissed others that have sent in resumes in recent weeks as "mostly rubbish".

UK lookalikes can earn around the £500 (NZ$1033) mark for half a day's work at parties, wedding shows, publicity stunts and shopping centre appearances.

Andrew Harvey, from Cambridge-based The Edge entertainment consultants, says he has another theory on the imbalance.

While many of the fairer sex want to be a princess, looking like a prince is not such a priority for most blokes.

"Wills are rarer than Kates, maybe girls are a bit more outgoing with these types of things," he says.

He has two Kates on the books and is still searching for a Prince William.

"On the big day, Kates will be able to make some money," he adds.

"It will be like new year's for pipers.

"There is a desire to look like Kate whereas Will, not such an aspirational figure."

Gene Daily, from Top Lookalikes, lost his Prince William a few years ago from "adult sudden death syndrome".

"He was perfectly healthy. It was a terrible tragedy. He was a lovely fellow," he says.

He says he has been unable to find a replacement that could do the royal justice.

Daily says he had a dream combination at one stage, with his late Prince William and "brilliant Prince Harry" being good friends.

But now he is finding it hard to get the right fit.

"There is a Prince William out there but I don't find him dependable," he says.

"There is a German one who is very popular in Germany but I find it hard to get past the German accent. Then there is the costs involved in getting him over here."