Heathrow’s third runway plans face delay after the Civil Aviation Authority capped early spending on the project.

The London airport is to launch an eight-week public consultation to finalise its proposals for expansion following the decision by the aviation regulator.

Heathrow now expects the £14 billion third runway to open between early 2028 and late 2029 if the plans are approved by government – against an original date of 2026.

Backers of Heathrow hub, an alternative scheme to extend Heathrow’s northern runway, renewed a call for prime minister Boris Johnson to announce an “urgent review” into the airport’s plans.

Heathrow said: “Capping spending has prolonged the construction period of a new third runway and means Heathrow will need to undertake refreshed modelling of key aspects of the plan – including public transport to and from the airport – to evidence that Airports National Policy Statement (ANPS) targets can be met.”

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The consultation will run from April to June, ensuring that communities can review and feedback.

Responses will feed into a final planning application, to be submitted “towards the end of 2020”.

The airport said: “Heathrow’s submission to the Planning Inspectorate will detail how the airport will expand and connect all of Britain to global growth, whilst meeting the requirements of the ANPS.

“It will also restate Heathrow’s commitment to ensuring an expanded Heathrow meets strict environmental targets, delivers tens of thousands of new high-skilled jobs and honours our commitments to local communities.”

Executive director for expansion Emma Gilthorpe said: “This country is ready for a decade of infrastructure delivery underpinned by expansion at Heathrow.

“We are keen to ensure our plans continue to be supported and shaped by local people as we prepare to deliver the economic boost Britain needs.”

Jock Lowe, of Heathrow Hub, said: “We always said that the rising costs of the complicated third runway plan would be a disaster, and so it has proved.

“The Department for Transport failed to adequately consider costs when it approved the third runway.

“But rising costs will inevitably fall on passengers and airlines via higher passenger fees at Heathrow, which are already the highest in the world. There is also a risk that taxpayers will have to foot the bill for billions of pounds of rail and road improvements.

“We have written to Grant Shapps, the secretary of state, to ask him and the prime minister to launch an urgent review into the third runway.

“Our extended runway proposal – which at only £4.7 billion for phase one is a fraction of the cost – is the only viable alternative which has been through the Airports Commission process and is capable of meeting environmental targets.”

“Heathrow expansion, done incrementally and with due consideration to environmental issues, is vital for the economy, to benefit passengers and to improve the resilience of the airport. The irony is that Heathrow Airport itself has made such a mess of it.”

Heathrow Hub is awaiting a judgement from the Court of Appeal on the government’s decision to support Heathrow’s third runway plan.