Millions of Londoners struggled to work on 6 August, as a strike by Tube staff brought the network to a standstill for the second time in a month over plans for a new night-time service.

Commuters turned to cars, boats, bicycles and packed buses, with the 24-hour walkout by rail unions meaning no trains were running on the network, which handles some four million journeys a day. The action follows a long dispute over the planned introduction of some 24-hour Underground services at weekends which are due to be launched on 12 September.

London mayor Boris Johnson apologised for the travel chaos across the British capital. "I'm very sorry about the disruption that is being caused. We're out there in force, volunteers all over the place trying to help people," Johnson said.

"We've got more buses, we've got more boats, we've got more bikes, and all that kind of thing, but clearly, for millions of people probably, it is going to be a tougher commute than normal," he added.

Johnson said the offer – an above-inflation 2% pay rise, a one-off payment of £500 ($776) and a promise that drivers would have the same number of weekends off – was "generous enough". Drivers will also keep their annual leave, which currently stands at 43 days.

"This is a very, very good deal. And that's not the way forward. The way forward is to look at the deal that's on the table, put it out to the membership," he said.

The London mayor has long been pushing for a 24-hour Tube service to be introduced in the capital.

"We're going to have to get London the night Tube that it needs. This is going to be a big improvement for our city. The five big main Tube lines will be running 24 hours a day; that's a prize worth fighting for," said Johnson.

All four unions taking part in the strike said they supported night services but said the plans would destroy their members' work/life balance.