Rachel Reeves is vowing to work with Sadiq Khan to fix Hammersmith Bridge if she becomes Chancellor.
However, she stopped short of pledging new money to get the historic bridge re-opened for traffic.
Giving the most detailed insights yet into what a Labour government would mean for the capital, she said around 650 out of 6,500 new teachers being pledged for the country would be in the city.
She declined to commit any more specific funding for the Met Police or City Hall.
But she highlighted some 1,300 more neighbourhood police and community support officers for London if Labour is elected, as well as a named police officer for every community so “people know where the buck stops”.
Progress on repairing Hammersmith Bridge has stalled as the Tory Government, Labour mayor, and Labour-run Hammersmith and Fulham Council have failed to agree a funded solution.
Ms Reeves told BBC Radio London: “A Labour government would work with the Mayor of London, would work with Labour local authorities, and Conservative local authorities, in London to fix some of the problems and we would work with Sadiq and the local councils to deal with those problems that I know exist around Hammersmith Bridge.”
But pressed whether she was promising better relationships with civic leaders rather than extra money, she added: “I’m not going to create pots of money without being able to say where the money is going to come from.
“I haven’t got a magic money tree.
“But I would work, if I were Chancellor for the Exchequer, and Lou Haigh as an incoming Transport Secretary, would work with the Mayor and local authorities to address the challenges that they face as well as providing longer term pots of funding for councils and mayors so that they can plan for the future and address the challenges they need.”
Londoners have been warned that it will be at least another five years before Grade II* listed Hammersmith Bridge can be reopened to cars, even if the £250 million estimated cost of fixing it is found today.
The bridge was shut to vehicles five years ago after its owner, Hammersmith and Fulham council, discovered its wrought-iron structure was riddled with cracks. Pedestrians and cyclists were temporarily banned the following year.
Pressed about Met Police chiefs warning of a funding blackhole in the force’s budget and the level of concerns about the rise in knife crime and women and girls’ safety, Ms Reeves declined to say there would be more funding.
“I totally understand the scale of the challenge that I would inherit if I become Chancellor later this year,” she added.
“We are not going to be able to fix everything straightaway.”
She explained further: “I’m not going to promise the world because it’s not possible to do everything straightaway.
“But those 13,000 extra police and community support officers will start to make inroads into tackling the high levels of crime and anti-social behaviour that people in London and in other cities and towns across the UK are experiencing.”
On the NHS, Labour is pledging 40,000 additional appointments every week to cut the waiting list backlog of more than seven million.
“Many of those appointments would be in our fantastic hospitals in the capital,” Ms Reeves added.
But the tightness of the public finances expected after the election and the scale of Labour’s promises were made clear by the fact that 650 extra teachers for London breaks down to just 20 more per borough.
The other “first steps” are to deliver economic stability, launch a new border security command to address “small boats” crossing the Channel, and set up Great British Energy.
Chancellor Jeremy Hunt has claimed taxes would rise if Labour wins power.
Ms Reeves has ruled out some tax increases and accused the Conservatives of making unfunded commitments.
Labour has said that it would charge private schools 20 per cent VAT, as well as ending business rates relief, to raise an estimated £1.7 billion, as part of its public spending plans.
