British Prime Minister Boris Johnson said on Wednesday he did not believe Britain was a corrupt country, as parliament was embroiled in a growing scandal over lawmakers being paid for external work which may have breached its rules.

The question of members of parliament (MPs) having second jobs has come under renewed scrutiny over the past week, after Johnson's government sought to change parliamentary conflict-of-interest rules to protect a colleague threatened with suspension.

Parliament's standards watchdog had determined Conservative Owen Paterson committed an "egregious case of paid advocacy" by using his position to promote two firms that paid him.

While Paterson ultimately resigned, Johnson's handling of the affair badly damaged party morale, and several leading names in the party are now under the media spotlight.

"I genuinely believe that the UK is not remotely a corrupt country nor do I believe that our institutions are corrupt," Johnson said during a news conference after a speech to try to convince leaders to go further in their pledges at the U.N. climate conference in Glasgow.

"What you've got is cases where, sadly, MPs have broken the rules in the past, may be guilty of breaking the rules today. What I want to see is them facing appropriate sanctions."

While Johnson has a majority of 77 seats in parliament, he is also facing pressure from a cost-of-living crisis as inflation rises, and a renewed bout of hostilities with Brussels over Northern Ireland that could damage trade ties.

CONSTITUENCY CASEWORK

Newspapers reported Conservative Geoffrey Cox, a former attorney general, used a proxy voting system set up to accommodate lawmakers working at home during COVID-19 to take part in votes from the British Virgin Islands, where he was advising its ministers in a corruption inquiry initiated by Britain's Foreign Office.

The Register of Member's Financial Interests, where lawmakers have to declare external earnings, shows Cox is paid hundreds of thousands of pounds a year for his legal work.

While carrying out external work is allowed, the Times newspaper published a video on Wednesday which appeared to show Cox taking part in a legal hearing from his parliamentary office, an apparent breach of the rules.

Opposition Labour Party deputy leader Angela Rayner described it as "a brazen breach of the rules and an insult to taxpayers" and said she had written to the Commissioner for Standards asking her to investigate the allegations.

In a statement, Cox's office said he always ensured his constituency casework was given primary importance and he had been advised by the Chief Whip, responsible for party voting, that his use of proxy voting was appropriate.

It said he would cooperate with any investigation. "He does not believe that he breached the rules but will of course accept the judgment of the Parliamentary Commissioner or of the Committee on the matter," the statement said.

Johnson declined to comment on individual cases when asked about Cox, but said those who were not putting the interests of their constituents first should face punishment.

The furore is reminiscent of the 1990s when Conservative Prime Minister John Major's government was hobbled by allegations of sleaze.

Britain's political establishment was similarly rocked in 2009 when a national newspaper published details of lawmakers' expenses, revealing widespread misuse which sparked public anger and led to some politicians going to jail.