SCOTTISH Labour will be letting down unionist voters if they allow the SNP to retain control of local authorities after May’s election, the Conservatives have warned, after Anas Sarwar ruled out "formal" coalitions with any parties.

Mr Sarwar, who has previously voiced his unease at Labour councillors working together with political opponents to run councils, has now told Labour group leaders that any "formal" deals with the SNP or the Tories will not be allowed.

The Herald understands that “no formal deals” will be allowed to be negotiated by Labour councillors following May’s crucial local elections – ending the party’s controversial coalition with the Tories in Aberdeen and the administration running Edinburgh in partnership with the SNP.

In Aberdeen, nine Labour councillors were suspended by then Scottish Labour leader Kezia Dugdale after the 2017 council elections after forming a coalition with the Conservatives and not having the move approved by the party’s Scottish Executive Committee (SEC).

Five years ago, the Tories replaced Labour as the second biggest party at local elections – winning 276 seats, ahead of Labour, who lost 133 places, on 262 councillors.

But Conservative local government spokesperson, Miles Briggs, has warned that Mr Sarwar’s point of principle will be letting down unionist voters – with the Tories appealing for May’s vote to send a message to the SNP on holding another independence referendum.

READ MORE: Tories plan ‘political earthquake’ and send indy message to SNP

Speaking to the Herald, Mr Briggs confirmed his party will not form any coalitions with the SNP, but insisted “we’ve been constructive”.

He said: “We’ve been flexible in saying what’s been best for communities – Aberdeen is that example.

“The councillors up there put their community and put the union first and we locked the SNP out of Aberdeen City Council and gone on to improvements and the council of the year across the UK.”

Mr Briggs added: “Anas is probably in a very difficult place because he’s trying to ride two horse in keeping his coalition of voters together but he probably has to pick a side at some point.

“If there’s an opportunity for the SNP to be kicked out, both in terms of losing seats and losing councils, I hope the Labour party do look towards where we can work together. That’s what most unionist voters in Scotland expected to see as well.”

A Scottish Labour spokesperson said: “Scottish Labour is committed to standing a full array of candidates who are committed to Scotland’s national recovery and protecting communities across Scotland.

“The fact of the matter is that it is this toxic Tory party led by Boris Johnson that is letting down unionist voters and weakening the fabric of the UK.

“Only Scottish Labour is on the side of all of the people of Scotland.”