The Conservatives have promised to commit more than £4bn to a fund for new bus and metro rail links in cities around England as the party competes with Labour over the improvement of public transport outside London.

A devolved local public transport fund would get an allocation of £4.2bn, with more promised as part of a wider Conservative commitment to spend £100bn on infrastructure.

It would be open to bids from eight mayoral or combined authorities: Greater Manchester, Liverpool City Region, West Midlands, North East, Tees Valley, West Yorkshire, Sheffield City Region and West of England.

A Conservative statement said that, while mayors and other local leaders would make the decisions over how to spend the money, projects that the fund was “expected to help” included a light rail system around West Yorkshire, and an expansion to Greater Manchester’s Metrolink trams to Stockport and Bolton.

Other mooted projects included upgrades to the Tyne and Wear metro, extending the West Midlands tram system, new or improved rail services around Sheffield, Liverpool and Bristol, and money to improve bus services in all the eight areas.

The announcement followed significant pledges on transport by Labour in recent weeks. The party has said if it wins a majority it will return the rail network to public ownership, with a massive programme of investment and to regulate or take ownership of bus services.

On Monday, Labour said it would use money from vehicle excise duty set aside by the Conservatives for road building but earmarked by Labour for green transport to reduce many rail fares, including commuter season tickets, by 33% in England.

Announcing the Tory plans the transport secretary, Grant Shapps, said: “These plans will change the face of local transport in towns and cities across the country. They will kickstart the transformation of services so they match those in London, ensuring more frequent and better services, more electrification, modern buses and trains and contactless smart ticketing.

“While Labour has confirmed it will raid the budget to build roads, the Conservatives believe in raising funding, improving quality and delivering value for commuters across the UK.”

Responding to the plan, Andy McDonald, Labour’s shadow transport secretary, said: “This announcement is a pathetic attempt to cover up the government’s disastrous and incompetent failure to invest in public transport.

“Tory cuts have caused public transport fares to rise at twice the rate of wages and thousands of bus routes to be cut, worsening congestion on our roads as a result.

“The north is set to receive £2,389 less per person than London on transport. The Tories have presided over an unbalanced and unequal economy.”