Police are investigating the Ukip MEP Janice Atkinson over suspected fraud, following claims that her senior aide asked hotel staff to make up a lunch bill for more than £3,000 so she could claim the money back at European taxpayers’ expense.

The party suspended the politician following allegations of a “serious financial nature”, and its leader, Nigel Farage, said the claims “couldn’t look worse”.

Kent Police said it is investigating after Ms Atkinson’s chief of staff, Christine Hewitt, was secretly recorded appearing to ask the manager of a restaurant in Margate, before Ukip’s spring conference, to more than treble the £950 cost of a meal.

Ms Hewitt is heard to say: “The idea is we overcharge them slightly, because that’s the way we repatriate it [from Europe].”

A member of staff replies: “£3,150, is that all right? Yeah, if you’re all right with that? Is that enough for you?”

Ms Hewitt responds: “Oh God yeah, that’s more than enough.”

Ms Atkinson, MEP for the South East, who was due to fight the Folkestone and Hythe seat in the general election on 7 May, has declined to comment. It is not known whether she knew of or authorised her aide’s apparent actions.

Mr Farage said yesterday: “It looks very bad – it couldn’t look worse and I’m astonished by it. I spoke to [Ms Atkinson] after midnight and she said it was all to do with bills and fundraising. I was, frankly, confused by it all. I simply couldn’t believe it – how on earth could anyone think they could behave like this?” Ms Atkinson faces a Ukip disciplinary hearing next week.

In a grim 24 hours for Ukip, the party suspended a second candidate following an “alleged incident in the workplace”. Stephen Howd, 49, a barrister, was representing Ukip in Scunthorpe.

A third, Jonathan Stanley standing in Westmorland and Lonsdale, resigned and accused Ukip of bullying.

Since 2010 the party has suspended at least 19 councillors, 14 parliamentary candidates, a national secretary, its youth leader, one spokesperson, its Scotland chair, an entire local branch, three MEPs and a local committee.

Name: Janice Atkinson

Janice Atkinson speaking to Ukip supporters in February (PA)

Position: MEP

Alleged offence: serious financial irregularities

Date of suspension: 19 March 2015

Resolved? Disciplinary hearing to be held ‘early next week’. Atkinson previously survived a race row after referring to a Thai constituent as a ‘ting-tong’. Nigel Farage ordered the MEP to apologise to the woman in person.

Name: Stephen Howd

Position: Scunthorpe PPC

Alleged offence: ‘incident in the workplace’

Date of suspension: 20 March 2015

Resolved? An investigation has been launched into the Leeds-based barrister.

Name: Amjad Bashir

Amjad Bashir said Ukip had become a 'party of ruthless self-interest' (PA)

Position: MEP

Alleged offence: ‘a number of extremely serious issues… which include unanswered financial and employment questions’

Date of suspension: 24 January 2015

Resolved? Yorkshire and the Humber MEP Bashir defected to the Conservatives on the day of his suspension effectively rendering Ukip’s investigation into him redundant. Ukip MEP Mike Hookem said he has passed on evidence of Mr Bashir’s alleged wrongdoing to West Yorkshire police.

Name: Roger Bird

Roger Bird, former Ukip general secretary

Position: General Secretary

Alleged offence: sexual harassment

Date of suspension: 9 December 2014

Resolved? Former Labour activist Natasha Bolter claimed Mr Bird had propositioned her during her selection process to become a Ukip parliamentary candidate. Mr Bird vigorously denied the claims and provided evidence showing the pair had been in a consensual relationship. He was cleared of wrongdoing on 23 December after an independent investigation but left the party by mutual consent.

Name: Winston Mckenzie/Lambeth and Croydon North branch

Political lightweight: Former boxer Winston McKenzie (PA)

Position: Branch Chairman

Alleged offence: misappropriation of donations

Date of suspension: 19 December 2014

Resolved? Mr Mackenzie and the local committee were suspended, along and the whole branch disbanded, following months of infighting culminating in accusations that £1,000 in donations had been misappropriated. An investigation found no evidence the funds had been misused but said proper procedures had not been followed. Mr McKenzie remains PPC for Croydon North but was “reshuffled” from his position as Commonwealth spokesperson comparing the move to a scene from The Godfather Part II. “I was Fredo on the boat. I was killed off my post,” he said.

Name: Brecon and Radnor branch

Position: Regional committee

Alleged offence: Bringing the party into disrepute

Date of suspension: 22 February 2015

Resolved? The row began when the branch elected just one person who was then elected its Westminster candidate. Ukip said correct procedure had not been followed and declared the selection invalid, suspending the entire branch. The row continues.

Name: Dave Small

Position: Councillor

Alleged offence: Sexist, racist, homophobic comments

Date of suspension: 27 May 2014

Resolved? Five days after becoming a Redditch Borough councillor, Mr Small was suspended after he was allegedly caught tweeting about “poofs and dykes”, “perverts” and “Pakis” prior to his election.

Name: David Silvester

(Henley Conservatives website)

Position: Henley-on-Thames councillor

Alleged offence: Homophobic comments

Date of suspension: 19 January 2014

Resolved? Blamed flooding on gay people in an interview peppered with homophobic remarks claiming homosexuality was a “spiritual disease” that can be healed.

Name: Robert Ray

Position: Chairman of Thurrock Branch

Alleged offence: Drink Driving

Date of suspension: 13 February 2015

Resolved? Mr Ray was caught drink driving after a session with Nigel Farage at a party fundraiser. He stood down as Chairman and is suspended from party activity while facing disciplinary proceedings.

Name: Lynton Yates

Position: PPC

Alleged offence: Inflammatory comments

Date of suspension: January 2015

Resolved? The suspension was lifted last month following comments made by the Charnwood parliamentary candidate that benefit claimants should be banned from driving. “These people really could catch the bus,” he said.

Name: James Moyies

Position: Councillor

Alleged offence: Bringing Ukip into disrepute

Date of suspension: January 2015

Resolved? The Ukip group leader on Southend council was expelled by the party last month after he and four colleagues voted to remove Ukip’s Westminster candidate from their council group.

Name: Godfrey Bloom

Former Ukip MEP Godfrey Bloom withdrew from the party after striking a journalist and calling women ‘sluts’ (AFP/Getty Images)

Position: MEP

Alleged offence: Sexist comments

Date of suspension: 20 September 2013

Resolved? Mr Bloom said women “didn’t clean behind the fridge enough” at a party conference meeting then said the room was “full of sluts” after female activists said they were too busy to do so. The ‘colourful’ MEP then hit journalist Michael Crick over the head with a conference programme in a row about racism. Mr Bloom quit the party a week later and stood as an independent MEP until leaving Brussels in July 2014.

Name: Chris Pain

Position: Lincolnshire county council party group leader

Alleged offence: Racist comments

Date of suspension: September 2013

Resolved? Mr Pain’s Facebook page carried racist comments but claimed his Facebook account had been hacked and cloned calling the comments “sick”. Police investigated but took no further action. Mr Pain was expelled from Ukip in a separate internal controversy and took four colleagues with him. He will represent ‘Independence from Europe’ in Boston and Skegness in May’s general election.

Name: Kerry Smith

Kerry Smith resigned as would-be MP for South Basildon and East Thurrock after it emerged he had mocked gay party members as “disgusting poofters”, joked about shooting people from Chigwell in a “peasant hunt” and referred to someone with a Chinese name as a “Chinky bird” (PA)

Position: PPC

Alleged offence: Homophobic remarks

Date of suspension: December 2014

Resolved? Mr Smith stood down as South Basildon and East Thurrock’s candidate after apologising for offensive remarks he made in a recorded phone call. The party said he left by “mutual consent”.

Name: Matthew Ellery

Position: Councillor

Alleged offence: Sexist comments

Date of suspension: May 2014

Resolved? The 23-year-old Basingstoke councillor was temporarily suspended after he was found to have called local women “pug ugly” while campaigning for his seat. He was arrested on suspicion of theft from his dad’s antique shop last week and is bailed until May – he quit the party this month.

Name: Rozanne Duncan

Ex-Ukip councillor Rozanne Duncan in the BBC documentary 'Meet the Ukippers' (BBC)

Position: Councillor

Alleged offence: Racist comments

Date of suspension: December 2014

Resolved? Ms Duncan, 68, was expelled last month told a BBC documentary that she had a problem with black people because there was “something about their faces”.

Name: Matthew Smith

Matthew Smith was one of three men standing trial at Norwich Crown Court the alleged electoral fraud (PA)

Position: PPC

Alleged offence: Electoral fraud

Date of suspension: 5 January 2015

Resolved? The 27-year-old Norfolk councillor was suspended ahead of a court appearance over alleged electoral fraud. He faces a retrial in June.

Name: Andre Lampitt

Position: Member

Alleged offence: Racist views

Date of suspension: April 2014

Resolved? The Zimbabwean decorator and star of Ukip’s 2014 election broadcast complaining about being undercut by “lads from Eastern Europe” was expelled after a number of “extreme racist views” were found on his Twitter account.

Name: Olly Neville

Olly Neville who was appointed as chairman of Young Independence at the end of last year (Facebook)

Position: Chair of Young Independence

Alleged offence: Gay marriage row

Date of suspension: 9 January 2013

Resolved? Claimed he was sacked as youth leader after defending gay marriage on Twitter as well as colliding with Ukip leaders over range of party policies.

Name: Harry Perry

Position: Member, prospective councillor

Alleged offence: Offensive comments

Date of suspension: 3 May 2014