Boris Johnson’s close relationship with Donald Trump could be dangerous for the environment with both leaders putting “short-term economic gains” ahead of longer-term climate issues, Jeremy Corbyn has said.

The Labour leader made his comments after meeting with fracking protesters in Blackpool, where he called on the prime minister to impose an immediate ban on shale gas extraction.

Corbyn has said Johnson’s “close alignment” with the US president could spell disaster for the planet, adding that the government would continue to miss climate change targets if no changes were made in strategy.

He said: “Well unless there is a real intervention by government on fracking, on measurements of emissions on aircraft and shipping … then we are deluding ourselves that we are actually adhering to climate change targets.

“Since he [Johnson] has no plans to do anything to protect it and is closely aligned with Donald Trump who claims that the Paris climate change accords are a danger to the American economy and that is a kind of signal to other industrial economies … well your short-term economic interests come ahead of the longer-term environmental issues.”

He also warned that fracking would harm the environment as he met protesters at the UK’s only active shale gas extraction site in Preston New Road, which has been the focus of long-running protests by green groups.

During a brief reprieve from the thunder and rain, Corbyn, with a cup of tea in hand, stood on a bench and addressed a crowd thanking them for their work and for drawing attention to the “dangers of fracking” calling for an immediate ban on the practice.

Labour said the UK risked missing the target of net-zero carbon emissions by 2050 if it continued to exploit gas reserves. The government said shale gas extracted from fracking had the potential to be “a new domestic energy source”.

But Corbyn said Labour would ban fracking and instead focus on creating a “green industrial revolution”, which would include investment in tidal power.

“We need urgent action to tackle the climate emergency, and that means the prime minister immediately banning fracking once and for all,” he said.

Jeremy Corbyn having tea with the protesters. Photograph: Christopher Thomond/The Guardian

He added: “I want to see fracking banned all over the country and I am determined to achieve it.”

The climate protesters Katrina Laurie, 41, and Netty Draper, 60, who have spent years campaigning against fracking in the area, met the Labour leader in a makeshift shelter where they told him they had been “through hell”.

Draper said: “He really listened to us. We want him to help us raise the profile of the anti-fracking movement and he has promised us that he will. We have spent so many years here monitoring what is going on and people in the whole country need to know about the impact fracking could have on their lives.”

The Preston New Road site began fracking in October but operations were halted on a number of occasions because of underground tremors. Cuadrilla said it expected to resume fracking by the end of August.

After visiting the fracking site Corbyn went to a community event in a nearby college focusing on his green industrial revolution.

Prior to the event he remained defiant in the face of criticism from Alastair Campbell. The former No 10 press chief to Tony Blair has written an open letter saying he no longer wishes to be a member of the party.

Corbyn said: “He’s written an extremely long letter to me. I read it with interest but I just say to Alastair and everybody else there is a Tory government – if you support Labour get out there and campaign for Labour.

“[I am] very confident of winning an election. I have been elected twice as leader of this party by a very large majority on both occasions. I hope the whole party will concentrate on the importance of challenging the most rightwing government we’ve had for a very long time, a government that is leading us into a cliff edge on Brexit, and the party should unite.”

A spokeswoman from the Department for Business, Energy and Industrial Strategy said: “Independent climate experts have recognised that natural gas has a role to play as we meet our 2050 net-zero emissions target – now firmly set in law.