Rishi Sunak's £100bn infrastructure vision will not be unveiled until after Budget

The plan to boost transport connectivity and work towards achieving net-zero emissions by 2050 had been set to be published "alongside" the Budget, which is due on Wednesday.

But Chancellor and Richmond MP Rishi Sunak, who took over at the Treasury last month, is now not expected to unveil the plans seen as being crucial to the Government's "levelling up" agenda until a later date.

Whitehall sources were unable to say when it would now be published, but expected the delay to only be a matter of days or weeks.

However, Labour's shadow chancellor John McDonnell said the delay represented "absolute chaos" in Government.

"We are facing the threat of climate change and an economy at risk of recession. That's why we desperately need an immediate start to large-scale infrastructure investment," he said.

"Delaying implementation of investment is unacceptable."

Sir John Armitt, chair of the National Infrastructure Commission, said they were "disappointed" at the delay but expressed confidence that ministers remained committed to infrastructure investment.

"Naturally we are disappointed about the further delay in the Government's formal response to the national infrastructure assessment, which we published over 18 months ago," he said.

"However, we are encouraged by the evident focus the Government wishes to place on investing in the UK's future infrastructure.

"Prioritising that investment within a long-term plan is key to success and if a short delay leads to a better strategy that more comprehensively addresses our recommendations, it will be worth the wait."

Meanwhile, a northern metro mayor has revealed how he use the WhatsApp messaging service to lobby the Chancellor.

Tory Ben Houchen, whose Tees Valley patch is next to Rishi Sunak's Richmond constituency, says he uses WhatsApp to message Sunak but doesn't always hear back.

"He doesn’t often reply because he’s a busy man, especially in the last couple of weeks. But he does read it, because the blue ticks come up," he told The Spectator. "I’m surprised he hasn’t taken that off yet in his new role — taking off the blue ticks."