Ms Collins told the Herald the installation of the doors was petty and unnecessary.
"We have been told that our previous arrangement that Annette King and I arranged when we came into Parliament after this last election - that we could walk down each other's corridors to use the lift and loo and kitchen - is no longer to be in place. And, as of next week, there will be these very expensive, lovely kauri doors put in to keep us from them, and them from us."
National's chief whip, Tim Macindoe, had told her and other affected National MPs that Labour had asked that the doors be put up.
Ms Collins said the doors would be controlled by swipe card, allowing press gallery members and others to pass through, but not MPs.
Mr Hipkins said Labour had simply accepted a proposal by National MP Gerry Brownlee after the election.
"Basically they wanted to take a bunch of offices off us ... which we reluctantly agreed to."
Mr Macindoe said he had been told yesterday by Mr Hipkins about the earlier proposal by Mr Brownlee, but he only became aware of the situation earlier this year when he was asked if National wanted the doors.
"I immediately canvassed National MPs on that floor who all agreed it wasn't needed, but we were subsequently advised that Labour MPs wanted it so it would be installed.
"To my recollection, at no stage did anyone mention to me what it would cost."