A multimillion-pound boost to UK companies was triggered by the Government’s backing for Heathrow expansion, according to the airport.

Bosses at the West London hub said that the process of investing £50 million in to the supply chain prior to the end of next year “has already started” after last week’s decision by a Cabinet sub-committee.

It is hoped this will result in the creation of up to 2,700 British jobs, including roles for engineers, architects and planning consultants.

The airport is planning to issue contracts worth £460 million before construction on the third runway is set to start in five years’ time.

Heathrow said 95% of the project’s procurement spending will be with the British supply chain, with 60% outside of London.

Trade union and business leaders gathered at Heathrow on Monday to commit their organisations to supporting the airport’s “fair and affordable” expansion until it is delivered, which is anticipated to be in 2025.

They will work with the Government to ensure that Britain begins to “reap the benefits” before 2020.

Heathrow chief executive John Holland-Kaye described the level of commitment from British workers and industry as “unprecedented”.

He continued: ” This weekend Heathrow started the process of pumping hundreds of millions of pounds into the British supply chain to build an airport that is fair, affordable and secures the benefits of expansion for the whole of the UK.

“Over the coming years, I look forward to working with our new partners to create thousands of decent jobs across the UK as together we deliver Britain’s new runway.”

The British Chambers of Commerce, the Confederation of British Industry, Unite and the TUC were among the dozen organisations whose representatives signed the third runway commitment.

It is a welcome boost for Heathrow, after a residents’ action group launched its own legal challenge against the go-ahead for the third runway.