Former MP Lembit Opik has been stripped of his coveted parliamentary pass for repeatedly breaking rules in a Commons bar, MailOnline can reveal today.

The Liberal Democrat, once tipped as a future party leader, is thought to be the first politician to have his privileged access to the Westminster estate withdrawn.

The punishment is particularly embarrassing as former members convicted of crimes and who abused expenses are still granted passes.

MPs who have served at least one full parliamentary term are eligible to apply for the 'Category X' passes.

Holders are entitled to use the subsidised restaurants and drink in the exclusive Strangers’ Bar - but cannot bring guests.

The scheme is intended to smooth the process of returning to civilian life, but questions have been raised about why 'zombie' politicians should still be entitled to access and the potential for lobbying former colleagues.

Former MP Lembit Opik has been stripped of his coveted parliamentary pass for repeatedly breaking rules in a Commons bar

Former members can apply for passes granting them access to the parliamentary estate - but they cannot bring guests

Mr Opik, 53, served as MP for Montgomeryshire for 13 years. After his defeat in 2010 he applied for and was granted a former members' pass.

But it was suspended in March this year after a cross-party committee of MPs found he had broken rules, and again in May due to a 'further breach'.

Mr Opik, who is now a TV and radio presenter, told MailOnline: 'They said that I had done something that was not allowed.

'I didn't intentionally break the rules. I have a lot of respect for the parliamentary estate. I think it is respectful to uphold this judgement.

'If they think I have done something wrong then I will accept that.'

He said the issue had been over taking guests on to the Commons Terrace, where MPs and staff often gather for a drink in the evenings.

'They said something like I had not followed the right protocol in having someone on the Terrace,' he said.

'Presumably they felt I had done the same thing again.'

Mr Opik added: 'You can argue about the nuances of it but the big point is that everybody has a responsibility to respect the regulations.'

A Commons spokesperson said: 'In March 2018 the Administration Committee suspended the pass of the former Member, Lembit Opik, for breaching the conditions of issue.

'The suspension was extended in May 2018 due to a further breach.'

Mr Opik is understood to be the only former MP to have their pass withdrawn since 2014, and there do not seem to be any examples prior to that.

Mr Opik, who famously dated one of pop duo the Cheeky Girls in the mid-2000s, has had a tumultuous time since being defeated in 2010.

Earlier this year his ex-girlfriend Sabina Vankova moved back to Bulgaria with their child, after a row over his close friendship with Alex Best, widow of football legend George.

According to the latest list of passholders, former Chancellor George Osborne and Nick Clegg have been granted privileges access to the Westminster estate.

David Cameron is also among a record 433 on the roster, including a host of Cabinet veterans who entered the private sector after leaving office, including Jack Straw, Geoff Hoon, and Alan Milburn.

Disgraced ex-ministers Chris Huhne and Jonathan Aitken are also passholders.

Former Deputy PM Nick Clegg (left) and George Osborne (right) have both been granted former members' passes, according to the latest list

Lib Dem ex-minister Chris Huhne (pictured) hold a pass despite being sentenced to eight months in prison in 2014 for trying to cover up the fact that he had swapped speeding points with his ex-wife

Earlier this year Mr Opik's ex-girlfriend Sabina Vankova (pictured right) moved back to Bulgaria with their child, after a row over his close friendship with Alex Best (pictured left), widow of football legend George

Lib Dem ex-minister Mr Huhne was sentenced to eight months in prison in 2014 for trying to cover up the fact that he had swapped speeding points with his ex-wife, Vicky Pryce.

Mr Aitken was jailed in 1999 for perjury and perverting the course of justice.

Tory Michael Trend, who in 2003 repaid £90,000 in wrongly claimed accommodation expenses, is on the list.

Several ex-MPs who left the House at the 2010 election following the expenses scandal also still have access.

Derek Conway had the Conservative whip withdrawn and then stepped down after being heavily censured for putting his son on the public payroll without apparently giving him any duties.

Labour's Ben Chapman declined to stand again after it emerged he had overclaimed on his mortgage by £15,000.

There is no suggestion that any of the individuals have breached rules - which explicitly ban lobbying.

In June 2015, 381 ex-members held a pass - up from 356 before the election that year.

As of October the figure had reached 414 and by last month there were 433.