Donald Trump sues former lawyer Michael Cohen for $500m over alleged contract breach

It comes following escalating attacks from Trump allies on Cohen, who is a key witness in a New York investigation.

Last week Trump was charged with fraud in relation to hush money payments to a porn star.

Legal action was filed in a Florida federal court accuses Cohen of making "improper, self-serving, and malicious statements about his former client, his family members, and his business".

Cohen, who was often described as Trump's fixer, worked as his attorney for over a decade and was also a vice-president at the Trump Organization.

However, the two fell out after the 2016 election, as investigators began looking into several of Trump's aides.

In 2018, Cohen was sentenced to three years in prison and a fine after pleading guilty to charges of fraud and campaign finance violations.

Following his release, Cohen has become a high-profile critic of the former president and a regular guest on news programmes.

He has written a book and also hosts a podcast, which Trump cites in the lawsuit.

"Mr Trump appears once again to be using and abusing the judicial system as a form of harassment and intimidation against Michael Cohen," Cohen's spokesman and lawyer, Lanny Davis told the BBC.

"It appears he is terrified by his looming legal perils and is attempting to send a message to other potential witnesses who are co-operating with prosecutors against him."

New York prosecutors have charged Trump with 34 felony counts of falsifying business records which they say was an effort to cover up payments intended to keep a porn star, Stormy Daniels, quiet about her alleged affair with him.

Trump appeared in Manhattan criminal court on April 4, as the first former US president ever indicted on criminal charges.

Cohen has since admitted that as Trump's fixer, he facilitated a $130,000 payment to Daniels.

He has made several appearances on major network news programmes and criticised his former boss.