Steve Rotheram has vowed to represent every part of the Liverpool City Region if he is elected its mayor next year.
Launching his manifesto, the Liverpool Walton MP and political aide to Labour leader Jeremy Corbyn vowed no borough would be left behind by devolution.
The date for the mayoral election has been set for 4 May.
Mr Rotheram was a councillor in Liverpool before being elected to Westminster in 2010.
He pledged to put aside "generations of tribal differences" with Manchester in order to develop a North West powerhouse.
He promised to create a lean and efficient mayor's office, and criticised current plans by the Liverpool City Region Combined Authority to spend £7m a year on staff and resources.
"I won't be spending £7m," he said. "I'll be trying to save every penny."
The Liverpool City Region covers five Merseyside councils - Liverpool, St Helens, Knowsley, Sefton and Wirral - as well as Halton in neighbouring Cheshire.
All six councils agreed a devolution agreement in November that will give the city region direct control over £30m a year in investment for the next three decades.
The mayor will oversee decisions on four key policy areas - economic development, transport, employment and skills, and planning for development.
Mr Rotheram said he has "a compelling vision to develop a new philosophy... to collaborate across those six areas".
He said he would invest in building council houses and transform transport by re-regulating bus services, providing new trains and "fighting for a connection to High Speed Rail 3".
The funding is "not a huge pot of money", he said, "but you can look for the multiplier effect on that" by entering into public-private partnerships on areas such as green and renewable energy.
He said the most important question he has been asked on the campaign trail is "what do you know about our area?" from people living in St Helens and Halton.
He said because he was born in Knowsley and worked as a bricklayer across the other areas, he understands the different types of cultures that will have to be "pulled together" when more power is devolved to the city region.
"It's not about being being just a Liverpool politician, it's about having that reach outside", he said.