David Mills, the estranged husband of culture secretary Tessa Jowell, is to face trial for allegedly perverting the course of justice, a judge ruled yesterday.

The lawyer will face trial in March next year alongside former Italian prime minister Silvio Berlusconi, who he worked for in the 1990s.

The two men are already facing trial next month on tax evasion and embezzlement charges. Both protest their innocence.

Mr Mills is accused of accepting $600,000 (£315,000) from Mr Berlusconi in 1997 in exchange for giving false testimony on the former premier’s behalf in two corruption charges.

It is in relation to these allegations that a Milan judge has decided they should face trial next spring. Both deny any wrongdoing.

Mr Mills separated from Ms Jowell in March amid a storm of publicity over the proceedings. Yesterday, foreign secretary Margaret Beckett said the culture secretary would not be “destabilised” by news of another trial.

“Despite the best efforts of many people to destabilise her, she has continued to do an excellent job, and I am sure she will continue to do an excellent job,” Ms Beckett said.

The prime minister’s official spokesman refused to be drawn on the affair, saying Mr Mills was a “private individual”.

Mr Mills told The Guardian last night: “The prosecution has known all along where this money came from, and I don’t know why they are proceeding with this.

“I am innocent, and the documents we have will prove this.”