A FORMER Scottish Labour donor stepped in to help a controversial Tory MP after he was threatened with legal action by the SNP’s Westminster leader, it has emerged.

Ian Blackford threatened to sue Ross Thomson in April after he mockingly referred to him in a Tweet as a “simple arms dealer” following disputed reports he profited from defence deals.

It led to Mr Blackford threatening to sue the Aberdeen South MP for defamation.

His solicitors demanded a public apology and a £1000 donation to charity.

Mr Thomson subsequently apologised in a private phone call to Mr Blackford and the matter was dropped.

READ MORE: Ian Blackford threatens to sue Ross Thomson over 'arms dealer' comment

The Times reported it followed Mr Thomson getting a legal opinion from QC Roddy Dunlop.

It has now emerged Mr Thomson’s £1800 legal bill was picked up by Aberdeen property tycoon Alan Massie, who had previously given £400,000 to the Labour party.

The latest register of MPs’ interests published by the House of Commons says Mr Massie provided a donation worth £1800 in the form of a “legal opinion from Faculty Services Ltd,” the company which provides administrative support for Scotland’s advocates.

It emerged last month that Mr Massie, 52, a director of the developer Calton Rock, had abandoned the Labour party after 30 years because of disaffection with its leadership.

He also endorsed Ruth Davidson as the best Scottish leader to defend the Union.

READ MORE: Aberdeen MP Ross Thomson is no stranger to controversy

Mr Massie had previously backed former Scottish Labour leader Kezia Dugdale, who was defended by Mr Dunlop in her recent court win over Nationalist blogger Stuart Campbell.

Mr Thomson’s Tweet echoed Mr Blackford’s infamous reference to himself last year in the Commons as a “simple crofter”, despite being an Edinburgh-born financier.

A spokesperson for Mr Blackford said: “We welcome that Ross Thomson deleted his tweet and phoned Ian Blackford to apologise, even if it was only after a talking to from members of his own party.

“Mr Thomson has gained a reputation for his offensive and completely unacceptable actions.

"We hope he will reflect on this pattern of behaviour, which continues to bring the Conservative Party into disrepute.”