POLITICIANS who break the law will be thrown out of parliament even if they serve less than a year in jail after ministers agreed to cross-party talks on the issue.

Under the current system, disgraced MPs and MSPs can be expelled only if they have been sentenced to more than 12 months,

But critics have demanded reforms following a series of high-profile cases, most recently that of former SNP MSP Bill Walker.

Yesterday it emerged that Walker is appealing against his conviction for domestic abuse offences against three former wives and a stepdaughter.

He was jailed for 12 months last September after being found guilty of 23 assaults and one breach of the peace. The sentence was the maximum available to the court.

But it meant the Scottish Parliament would have been powerless to expel him had he not resigned as an MSP for Dunfermline after his conviction.

Any changes to the Westminster rules are expected to be adopted at Holyrood, as well as in the Northern Irish and Welsh assemblies.

The UK Government has offered to open discussions with Labour over potential changes to the rules. Labour sources said they expect talks will centre around a sensible alternative. They are keen to secure the expulsion of MPs who bring parliament into disrepute without affecting those jailed for very short periods as a result of political protest.

Some have called for the limit to be cut to just six or mine months.

But women's groups and others favour a system based on the crime itself, not the length of the prison sentence.

Thomas Docherty, the Labour MP for Dunfermline and West Fife, who has campaigned on this issue, said that he was "open minded" on outcome of talks.

He added: "There needs to be genuine discussion about what the new rule would look like.

"We have to recognises the right to protest and cases like Caroline Lucas [the Green MP who recently pleaded not guilty to offences allegedly committed during anti-fracking protests last summer].

"But my constituents are clear that they want the limit to be less than one year."

Andrew Lansley, the leader of the House, told Labour MPs last week he supported cross-party talks on the issue. He said: "I would want to proceed on the basis of an understanding of consensus and I will be glad to discuss the question with colleagues, the shadow Leader of the House and others."

Lily Greenan, manager of ­Scottish Women's Aid, said: "We would welcome talks on this issue.

"Our issue was the nature of the offence, rather than the length of sentence, because it is rare to get a custodial sentence for domestic abuse".