“DANGEROUS and foolish” London Mayor Boris Johnson was in the firing line yesterday after he shelved the September launch of all-night London Underground trains.

Four Tube lines were due to start running throughout Friday and Saturday nights from September 12, but the mayor has been locked in dispute with unions over new rosters.

London Underground (LU) managing director Nick Brown said that bosses had agreed to defer the launch as they were “not far from an agreement” with workers.

“Our objective is to reach an agreement that ends this dispute and delivers the Night Tube for Londoners this autumn,” he said.

Tube unions RMT, TSSA and Unite called off two days of strike action this week after movement in negotiation meetings, following two earlier strikes which totally shut down the Tube network.

But the Underground could face walkouts on September 8 and 10 if a settlement is not reached by then, RMT warned.

“This move by Transport for London proves that our members were right to strike and were right to warn the public about the consequences of the mad rush to introduce the mayor’s Night Tube plans without agreement,” said RMT general secretary Mick Cash.

“We warned repeatedly that it would be dangerous and foolish to press ahead with bodged Night Tube plans until the very basics in terms of staffing and safety had been agreed with the unions through the long-established frameworks.

“The fact that the plans have now been suspended indefinitely to some vague date ‘in the autumn’ is clearly a massive embarrassment to both Boris Johnson and George Osborne.”

Labour London Assembly transport spokeswoman Val Shawcross blamed the delay on Mr Johnson “hiding on the sidelines” rather than leading negotiations with unions.

“If you try and launch a major project without speaking to the people you’ll be relying on to deliver it, it’s never going to end well,” she said.

Aslef general secretary Mick Whelan said: “Had LU not acted in bad faith, by trying to introduce the Night Tube in London without consultation and without negotiation, we wouldn’t be where we are today and they would have been in a position to deliver.”