Tommy Robinson could make more than £1m from a potential trip to the US next month, making him one of the best funded far-right figures since the second world war, an analysis by anti-fascist campaigners says.

The English Defence League founder, whose real name is Stephen Yaxley-Lennon, has been invited to give an address in Washington by members of Congress and is waiting to see if US authorities will grant a visa for the event, scheduled for 14 November.

The Middle East Forum (MEF), a US neo-conservative thinktank, and the rightwing David Horowitz Freedom Center invited the 35-year-old, who, despite repeatedly falling foul of the British justice system, has growing support in the US. Robinson is on bail after being charged with contempt of court, and has a string of previous convictions in Britain.

Joe Mulhall, a senior researcher at Hope not Hate, said: “The inevitable media coverage that will surround the visit will no doubt lead to an increase in his already significant monthly donations from America.

“We believe that, should he be allowed to enter the US for this event, he stands to make in the range of £1m in donations with the potential for much more. America offers the opportunity for further large-scale investment in Lennon.”

“Both the organisations that have invited Lennon to the US have a history of donating large amounts to European anti-Muslim individuals and organisations.”

MEF donates $2m (£1.6m) annually to primarily rightwing causes and has contributed to Robinson’s legal fees. David Horowitz is also a significant donor to anti-Muslim causes and in 2015 donated £90,000 to the far-right Dutch politician Geert Wilders.

Former assistants to Robinson recently claimed he had secured a “massive payday” after being jailed for contempt in May, earning hundreds of thousands of pounds in donations.

Hope not Hate warns that Robinson will earn massive sums in donations that it fears will be used to fund a future UK tour in which he will attempt to sow community tensions.

The sums that far-right activists are raising are unprecedented in modern times. Recent data shows that alt-right figure Stefan Molyneux drew more than £1m from his Bitcoin wallet between February 2013 and January 2018. Robinson, says Mulhall, is significantly more high-profile than Molyneux and stands to make a huge amount in donations.