Crossrail’s chairman has stepped down just days before being questioned along with the Mayor of London facing the London Assembly’s transport committee over the disastrous 10-month delay in the ‘super tube’ opening.

East London Advertiser: Whitechapel Crossrail escallators being laid out... now Mayor Khan is to be quizzed over long delay in the line opening. Picture: John Zammit and (inset) GLAWhitechapel Crossrail escallators being laid out... now Mayor Khan is to be quizzed over long delay in the line opening. Picture: John Zammit and (inset) GLA (Image: John Zammit)

Mayor Sadiq Khan has been summoned to face Assembly members on December 21, the first time the committee has used such powers.

He appears as statutory chairman of TfL, the transport authority that will operate Crossrail’s £15 billion Elizabeth line to Heathrow with interchange stations ready to open across London, including Whitechapel and Canary Wharf.

The summons also requires London’s transport commissioner Mike Brown to attend with the mayor.

Crossrail chairman Sir Terry Morgan was “invited to attend”, but it has now emerged that he has resigned, according to the Department for Transport today.

East London Advertiser: Crossrail's Whitechapel station construction in 2017, with questions now raised over 10-month delay in opening. Picture: Mike BrookeCrossrail's Whitechapel station construction in 2017, with questions now raised over 10-month delay in opening. Picture: Mike Brooke (Image: Mike Brooke)

Key questions Assembly members want answered concern the postponed opening which is not expected for another 10 months, and why this was kept quiet for 16 weeks before it leaked.

“We are bitterly disappointed that this action is necessary,” the Assembly’s transport chair Caroline Pidgeon said in a statement today.

“The mayor must come clean over when he knew about the delay. The public puts trust in transparency, but the only thing that’s become clear is the opposite when it comes to Crossrail.”

Refusing or failing to attend Assembly proceedings as required by a summons notice without a reasonable excuse is “a criminal offence”, City Hall points out.

East London Advertiser: Chris Grailing putting last piece of track in place at Whitechapel, watched by London Assembly's Val Shawcross and a Crossrail engineering apprentice. Picture: Mike BrookeChris Grailing putting last piece of track in place at Whitechapel, watched by London Assembly's Val Shawcross and a Crossrail engineering apprentice. Picture: Mike Brooke (Image: Mike Brooke)

The committee’s unprecedented move follows conflicting statements from the Mayor’s Office and Crossrail on “who knew what and when” about the delayed opening.

It was the Transport Secretary Chris Grailing who first revealed December 18 as the opening date, in an exclusive interview with the East London Advertiser in October 2017.

But 14 months on, the opening has been pushed back to September next year.

Further questions are being raised about costs, originally put at £15bn, now thought likely to add another £1bn to the bill when the Elizabeth line finally opens.

It is being paid for by Whitehall and by business rates, with no EU funding, the Transport Secretary said when he visited the construction site 150ft under Whitechapel. Brexit would have “absolutely no effect on Crossrail”, he said at the time.

Documents also being scrutinised at next week’s transport special session at City Hall include briefings given to the mayor on a possible delay.

The Elizabeth line is designed to relieve the overcrowded Central line with high capacity trains that can each seat 1,500 passengers, almost double the traditional tube train capacity, and running at 24 an hour at peak time.

Passengers at Whitechapel going west will arrive at Heathrow in just 39 minutes, with stops along the now-completed deep tunnel route at Liverpool Street, the City and West End before it joins the Paddington main line on the surface.

The line splits at Whitechapel going east with one branch to Canary Wharf, Silvertown by London City Airport and under the Thames to Woolwich and Abbey Wood, the other to Shenlfield, joining the commuter route at Stratford above ground.