Heathrow has submitted its “shovel-ready” plans for a third runway as part of a £50bn investment, as the government said expanding Europe’s largest airport could create 100,000 jobs and drive growth.

The 2-mile (3.2km) runway expansion would cross a diverted M25 and allow more than 750 additional flights a day over London, helping bring the total annual number of passengers to 150 million.

Environmental campaigners called it a “doomed scheme” that would release millions of tonnes of CO₂ while benefiting only a small minority of rich flyers.

Heathrow said that with government support it could obtain planning permission by 2029 and have the runway in operation by 2035.

Its proposals remain essentially the same as those submitted in 2019 and approved in principle by the government and MPs. That scheme survived a brief block on climate grounds sparked by legal challenges from campaigners, overturned on appeal in 2020.

However, the plans were put on hold as passenger numbers dropped during the pandemic. The shareholders in the airport, which include the French private equity firm Ardian and Saudi Arabia and Qatar’s sovereign wealth funds, are seeking legislative change, as well as long-term political support, before filing a full planning application.

Rachel Reeves, the chancellor, has strongly endorsed expansion, but Heathrow is seeking firm policy guarantees after previous runway plans were overturned.

These include airspace modernisation to ensure extra flight paths and the passing of the planning and infrastructure bill. The airport is also seeking guarantees that the aviation regulator, the Civil Aviation Authority (CAA), would allow Heathrow to levy charges to airlines at a level high enough to recoup its investment.

Heathrow said the price of the runway itself would now be £21bn, up from £14bn six years ago, due to inflation in construction costs. An additional extension of Terminal 5 to support the extra passengers would cost £12bn, while another £15bn spend is planned to upgrade the wider airport regardless of the runway development.

The chief executive of the airport, Thomas Woldbye, said it had “never been more important or urgent to expand Heathrow”.

He said: “We are effectively operating at capacity to the detriment of trade and connectivity. With a green light from government and the correct policy support underpinned by a fit-for-purpose regulatory model, we are ready to mobilise and start investing this year in our supply chain across the country. We are uniquely placed to do this for the country. It is time to clear the way for takeoff.”

A government spokesperson said: “Expanding Heathrow could drive growth, trade and tourism, whilst unlocking over 100,000 jobs.”

The government has promised to review the plans over the summer, with Heathrow pressing for a green light in September. It will also examine a rival proposal from a developer, the Arora Group, which has drawn up plans for a shorter runway further to the east.

A Heathrow spokesperson said the airport was open to discussing with airlines the potential for a shorter runway, but it did not believe alternative schemes could reduce the cost or deliver the same benefits as the existing plans.

The hub’s expansion is backed by business groups and unions, as well as the government, despite arguments that unchecked aviation growth is incompatible with Britain’s net zero ambitions and tackling the climate emergency.

The CBI, British Chambers of Commerce, MakeUK and the Federation of Small Businesses said in a joint statement that the third runway “opens up vital access to major and emerging markets [and] unlocks billions in private investment, strengthening supply chains, creating jobs, and driving skills across the country”.

Heathrow claims expansion would also create more competition. British Airways currently operates half of all flights from Heathrow and airlines jealously guard rights to valuable slots. EasyJet said the runway represented “a unique opportunity for easyJet to operate from the airport at scale for the first time and bring with it lower fares for consumers”.

However, opponents questioned whether the scheme would progress, having failed to move ahead so far despite approval from two previous governments.

Paul McGuinness, the chair of the No 3rd Runway coalition, said: “There’s a real danger that we’ll end up with a hole in the ground and a debt pile for taxpayers to underwrite, because the government had foolishly encouraged Heathrow’s profligate self-interest, as if blind to the lessons of HS2.”

The mayor of London, Sadiq Khan, said a new runway would have “a hugely detrimental impact on our environment”.

Dr Douglas Parr, the policy director for Greenpeace UK, said the announcements meant residents around Heathrow would have “their lives put on hold for a few more years while more money and time is wasted on a doomed scheme … the economic case for the whole debacle just will not fly”.