Transport for London has again denied that work on the Metropolitan Line Extension has been suspended after reports that work was on hold indefinitely.

A TfL worker told the Observer that his manager said work on the line has been suspended. He said this is because Mayor of London Sadiq Khan has concerns over the budget and until TfL can come up with the funding, work is suspended.

Suspicions were raised last month when Mr Khan failed to mention the extension – that would extend to Watford - in London’s travel agenda.

Mr Khan outlined how TfL will save more than £3 billion over the next four years – completely omitting the £284.4m plan to extend the Met line.

But TfL are denying the suspension and said they are still reviewing their business plan and have a fund that “could” cover the line.

David Hughes, London Underground’s director of strategy and service development, said: “Since taking over the Metropolitan Line Extension in November 2015, we have undertaken substantial design development and enabling work, which is due to complete in spring next year.

READ MORE: Have plans to extend the Metropolitan Line derailed?

“We continue to work with Hertfordshire County Council and DfT to ensure the affordability of the project.

“There’s a growth fund in the Business Plan for transport projects which will unlock growth and regeneration. The list of projects covered by the fund is still being reviewed but could include the Metropolitan Line Extension.”

The TFL business draft plan included plans to extend the Bakerloo Line, expand the Night Tube and open the Elizabeth Line but the Met Line extension was left out the document.

The previous plan was published in March by the outgoing London Mayor Boris Johnson and it specifically mentioned the extension.

Previously known as the Croxley Rail Link, the project was managed by Hertfordshire County Council until March last year when London Underground announced it was to take over responsibility.

Mayor Dorothy Thornhill said she has not been told work has stopped but Hertfordshire County Council and the other stakeholders are meeting on Friday to discuss the extension.

She said: "As far as I'm concerned, work is continuing. I've not been told that work has been suspended. We are all concerned about the shortcoming in the funds but I think the project has come too far for them to stop it now.

"We're worried enough to have a meeting about the shortcomings with all the stakeholders, but this is to make sure we take the appropriate action and ask the right questions."

The £284.4m cost includes a local contribution of £125.4m, £109.8m from the Department for Transport and £49.2m from Transport for London.

The local funding includes £87.9m from the Hertfordshire Local Enterprise Partnership, which represents 40 per cent of its total Growth Deal funding from the government.

Sadiq Khan was contacted for a comment but has not responded.