Mr Pennycook told the committee: “I must make it clear that delivering 1.5 million homes initially will be more difficult than we expected in opposition.”

The Greenwich and Woolwich MP accused the previous government of a “difficult legacy”, citing Office for Budget Responsibility (OBR) predictions that total supply would fall below 200,000 this year.

Mr Pennycook said the Government would not set annual targets for new homes and said: “We are in a hole, we have to dig ourselves out of it. “This will take time.”

But Mr Pennycook said he was “convinced” the 1.5 million homes target was “achievable”.

He said: “Both the Deputy Prime Minister and I have never been entirely candid that 1.5 million net additional homes in one parliament is an incredibly challenging target.

“Of course we could have chosen a much less taxing target… but in our view doing so would have been an inadequate response to the acute and deep-seated housing crisis in the UK.”