A former Ukip MEP has been found guilty of fraudulently claiming nearly £500,000 in European parliament expenses, by a jury at Southwark crown court.

Ashley Mote was found guilty of 12 fraud-related offences, all of which took place between 2004 and 2010, and of using the gains to fund his court battles in the UK. Mote was suspended from Ukip in 2004, shortly after he was elected, when the party discovered he was facing separate charges for benefit fraud.

Mote was released on bail on Friday, but the judge, Justice Stuart Smith, said there was a strong likelihood that he would be given a custodial sentence.

A spokesperson from Ukip said that the offences Mote had been found guilty of on Friday dated from after he had been expelled from the party and they welcomed the verdict. “I’m astonished that this case has taken so long,” the spokesperson said. “Justice must be done and justice must be seen to be done.”

The prosecution claimed that Mote submitted numerous false claims for parliamentary assistance allowances for payment for work that organisations had carried out on his behalf.

The jury took an hour and 42 minutes to find the 79-year-old guilty, which Smith described as a “relatively short time”. He told the jury: “I have watched you over the four weeks [of the trial] and you have been giving this close attention.”

Mote was elected as a Ukip member of the European parliament for the constituency of South East England in 2004, campaigning against Brussels sleaze. The party expelled him, leaving him as an independent MEP, when they found out he was facing charges for allegedly claiming £32,000 in income support and £35,000 in housing benefit from Chichester district council over a six-year period.

The subsequent trial attracted significant media attention as Mote attempted to claim immunity from prosecution on the basis that he was an MEP. Mote was found guilty of benefit fraud and sentenced to nine months in prison in 2007, with the judge describing him as “a truly dishonest man”.

As Mote’s sentence was less than a year he was permitted to keep his seat in the European parliament, something Nigel Farage condemned, saying: “If Mote had a shred of integrity left, he’d resign.” Mote sat as an independent MEP until 2009, when he decided not to stand for re-election.