Lutfur Rahman, Britain's first directly-elected Muslim mayor, is due to go before the elections court today.
He is accused of fraud in the run-up to the Tower Hamlets mayoral election in May 2014.
Tower Hamlets First says the Mayor's top priority is continuing to provide high quality public services for residents.
The election could be re-run if Mr Rahman is found guilty.
Robert Radley will outline detail of tests he carried out following elections in Tower Hamlets, east London, in 2014.Read the full story ›
A Labour candidate who stood in the Tower Hamlets election last year has told a special Election Court that she was 'appalled' by the behaviour of supporters belonging to the party set up by the winning mayor Lutfur Rahman.
Victoria Obaze, who was standing in the Stepney Green ward, submitted a witness statement in which she said she saw supporters of the Tower Hamlets First Party blocking the way into a polling station so the police had to be called three times. She said she also the activists accompanying voters into the polling station to show them how to vote.
The trial begun after four people from Tower Hamlets made a series of allegations about the way the Tower Hamlets First party operated. Mayor Rahman has said there is 'little if any' evidence against him.
Tower Hamlets Mayor Lutfur Rahman, who is accused of "corrupt and illegal practices" in his re-election, is the victim of "downright deliberately false allegations" his lawyer said today.
Duncan Penny QC told a special hearing in the High Court says there is "little if any" evidence of wrong-doing against the 48-year-old Independent candidate.
He said the allegations of "electoral fraud" bought by four Tower Hamlets residents were a mixture of invention, exaggeration and falsehood.
Mr Penny QC said the "one aim" was to unseat a "directly elected mayor".
The re-election fraud hearing of Tower Hamlets Mayor Lutfur Rahman has opened at the High Court before election judge Richard Mawrey.
ITV News London Correspondent Simon Harris is at the hearing, where Francis Hoar, the barrister for the petitioners, has described Mr Rahman's denial of any wrongdoing as "laughable".
Hoar: Rahman will claim 'I know nothing' about fraud. 'Explanation is so poor as to be laughable.' @itvlondon
Hoar plans to call 100 witnesses. He claims some have had threats of violence and threats to their families in Bangladesh. @itvlondon
Mr Rahman has previously issued a strong denial against the claims: "There is simply no evidence to substantiate that the recent election results were due to fraud and intimidation," he said. "It is clear that these complaints are being generated by disgruntled candidates who lost."
A High Court trial challenging the re-election of Tower Hamlets Mayor Lutfur Rahman opens today.
Mr Rahman, 48, is accused of winning May's election through "corrupt and illegal practices".
A leading forensics expert expected to give evidence during the hearing has conducted electrostatic document analysis (Esda) tests on postal ballot papers marked with votes for Mr Rahman, The Telegraph reported.
The petition against Rahman, an independent candidate, was brought by Tower Hamlets residents Andy Erlam, Debbie Simone, Azmal Hussein and Angela Moffat.
Mr Erlam, who stood as a councillor on an anti-corruption ticket, says there are "serious questions" which "need answers" and is calling for a re-run of the election.
Mr Rahman denies any wrongdoing.
Former Mayor of London Ken Livingstone, George Galloway and members of the new left wing political party Left Unity are meeting today to discuss communities secretary Eric Pickles' appointment of three commissioners to oversee the running of Tower Hamlets council.
They say the move is an attack on local democracy.