A PETULANT George Osborne vowed to press on with cuts to tax credits yesterday despite his detested policy’s progress being thwarted by peers.

The Tory Chancellor’s plan to slash the incomes of 3.3 million families by £1,300 a year on average was twice defeated in the Lords on Monday night.

Letters due to land on doorsteps days before Christmas telling claimants of the cuts have now been delayed, a Downing Street spokeswoman conceded.

And Mr Osborne will now be forced to provide transitional protection from his cuts before his Autumn Statement on November 25.

But he put Britain’s poorest families on notice that he was “determined as ever” to take away cash they depend on to stay out of poverty.

“We will continue to reform tax credits and save the money needed so that Britain lives within its means, while at the same time lessening the impact on families during the transition,” he said.

“I will set out the plans in the Autumn Statement.”

The resentful Chancellor declared his intention to ignore public opposition to any cut during a fiery Treasury questions dominated by tax credits.

He also lashed out at the Lords, claiming their rejection of his cut “raises clear constitutional issues which we will deal with.”

But Labour MP Wes Streeting told him to “put his toys back in the pram” and go back to the drawing board “instead of manufacturing a phoney constitutional crisis.”

And shadow chancellor John McDonnell said that tax credits are “not a constitutional matter” for the low-wage workers set to lose up to £3,000 a year.

Mr McDonnell put before the Chancellor Labour’s proposals to save £4 billion without cutting tax credits.

“He can push on with his tax giveaways to big corporations and the wealthiest,” he said.

“Or he can reverse those tax breaks to the few and go for a lower surplus target in 2019-20 while sticking to his self-imposed charter, and still be in a position to not hit three million working families with these tax credit cuts.

“The ball is now in Osborne’s (half of the) court.”