Former British Prime Minister John Major slammed fellow Conservative Boris Johnson’s handling of a corruption scandal on Saturday, saying the government’s actions were arrogant, violated the law, and were “politically dishonest.”

Johnson was forced to backtrack after abandoning proposals pushed through parliament to safeguard a legislator who was discovered to have violated lobbying regulations.

Major, Britain’s prime minister from 1990 to 1997, claimed that his party had ruined parliament’s credibility. The former premier, whose own government was accused of graft, said he would be torn about voting for Johnson in the next election.

“I think the way the government handled that was shameful, wrong and unworthy of this, or indeed any government,” he said in a BBC interview.

“There’s a general whiff of ‘we are the masters now’ about their behavior,” he said. “They also behaved badly in other ways that are perhaps politically corrupt.”

A spokesperson for Johnson said paid lobbying was wrong and elected officials must abide by the rules.

The row has raised fresh questions about Johnson’s ethics. He has faced other accusations of wrongdoing, including plans to have party donors secretly contribute to a luxury renovation of his Downing Street flat.

Johnson has said the government followed the rules over the refurbishment.

A poll published by the Daily Mail on Saturday found 57% of voters said they agreed with a statement made by the prime minister’s adviser on ethical standards this week that Britain could “slip into becoming a corrupt country”.

Major, who campaigned to keep Britain in the European Union and who criticized Johnson over this handling of Brexit, said Johnson’s behavior could harm the party in the future.

“They have broken their word on many occasions,” he said. “I have been a Conservative all my life and if I am concerned at how the government is behaving, I suspect lots of other people are as well.”

Major also said Johnson would be “colossally stupid” if he followed through on threats to use emergency powers to suspend parts of the Northern Ireland protocol, part of the Brexit deal at the center of a dispute with the EU.