Nicola Sturgeon has urged "concrete" action by the UK Government against the criminal abuse of Scotland's notorious limited partnerships.

The First Minister was speaking after The Herald revealed Theresa May was set to ban the once obscure form of firm nearly a year after this newspaper revealed they were at the heart of multi-billion-dollar Russian money-laundering.

Campaigners and opposition politicians are still waiting to hear specific proposals on SLPs. The Prime Minister, however, on Wednesday formally made it known to the SNP's Westminster leader Ian Blackford that she is ready to act.

Speaking at First Minister's Questions, Ms Sturgeon said: "Scotland has a strong international reputation for financial services and it is important to prevent SLPs being misused for criminal purposes."

She added: "To reinforce how seriously we take this issue I have today written to the PM requesting her to take immediate steps to reform the law in this area."

Conservatives had already singalled they would act on SLPs under constructive pressure from the SNP and Scottish ministers and with support of key Labour figures.

The recent Salisbury attack - and the desire to hit back at the associates of Russian President Vladimir Putin - is understood to have "focused" the prime minister's mind.

The UK last June forced all SLPs to declare a person of significant control in emergency legislation. In Holyrood, Ms Sturgeon said this was an "important first step". 

However, she added: "There continues to be revelations of criminality being facilitated througth SLPS. More does need to be done by the UK Govt. This is a reserved area. So we will continue to press them to take concrete action."

The first minister also praised her own SNP team in Westminster, led first by Roger Mullin and then Alison Thewliss, and The Herald for their work to convince the Conservatives to act. 

She said: "I think it is also appropriate to take the opportunity to acknowledge the persistence of colleagues at Westminster, David Leask at The Herald newspaper and the efforts of them and others to keep this issue in the public eye."