But she claimed any prospect of growth would be “destroyed” by the government’s Employment Rights Bill, which she said would place more burdens on business.

In her speech in Oxford, Reeves sought to inject some optimism and confidence into the economy, which has taken a battering in recent months as growth has flatlined.

She hit back at Conservative claims that her “job destroying” Budget was to blame, insisting she had “no alternative” but to increase employers’ National Insurance to restore stability.

She did not explicitly rule out further tax increases in the spring – but insisted the government had “begun to turn things round” and was determined to go “further and faster” to boost growth.

She described the UK as a country of “huge potential” which had been “held back” for “too long” because politicians lacked the “courage” to challenge the status quo.

“Low growth is not our destiny, but growth will not come without a fight, without a government willing to take the right decisions now to change our country’s future for the better,” she added.

The government has made growth its top priority because so many of its other plans – to improve public services and living standards, as well as its chances of winning the next election – depend on it.

Ministers insist advances in aviation mean a third runway would not break its carbon reduction rules – but it is still being fiercely resisted by environmental campaigners and Labour’s London Mayor Sadiq Khan.

In an interview with the BBC’s economics editor Faisal Islam, Reeves said she wants a planning application for a third runway at Heathrow “signed off” before the next election, which must happen by 2029.

She said she wanted to “get going sooner than that” on the next phase of an East-West rail project that will eventually connect Oxford directly to Cambridge, via Milton Keynes and Bedford.

“I want spades in the ground. I want people to see in their areas, things happening, growth happening, their children and their grandchildren in the future having the opportunity to work in high-skilled high-paid jobs contributing to the economy with more money in their pockets,” she told the BBC.

Earlier she claimed the new Oxford and Cambridge “growth corridor”, which includes new reservoirs to address water shortages in the area and investment in high tech industries, would add up to £78bn to the UK economy by 2035.

Other projects announced today include a major redevelopment of Old Trafford, the area around a new stadium for Manchester United, and a plan to bring Doncaster/Sheffield airport back into use and boost industry at East Midlands airport.