To combat pressure from England’s neighbours, Mr Burnham has been urged to stand firm and ignore the nationalists’ attempts to lobby for independence referendums.
One former Labour MP said: “What is needed is any Government to actually say, No, f**k off’. You have all the power you have got to get. Play the game or f**k off the pitch. And that is all that’s needed.
As soon as you start even talking about independence, let alone a referendum… you’re immediately giving them the oxygen and publicity they don’t deserve. By doing that, you’re actually screwing the Labour in Scotland and Wales.”
Darren Millar, the Welsh Conservative leader, added: “Instead of constitutional meddling, Mr Burnham should focus on the public’s priorities of growing the economy, reducing the welfare bill and investing in our national security.”
A Government spokesman said: “The Prime Minister has announced a National Commission on Electoral Reform so our voting system can give power to people in every postcode.
“Political parties will have the chance to participate and the Commission will report before the next general election.”
GB News has approached the SNP and Plaid Cymru for comment.