Labour's shadow foreign secretary Douglas Alexander will today call on Scottish politicians to be "opponents, not enemies" as the independence debate continues to intensify.

In a keynote speech, Mr Alexander will also call on the SNP to help Labour to improve devolution if there is a No vote in September.

The call will come in a speech to mark the 20th anniversary of the death of the former Labour leader John Smith.

Mr Alexander is expected to say: "I want to suggest [Labour] must do more than be a voice of hope in the coming months.

"We must also be a voice for - and partner in - ­reconciliation in the years that follow."

He will go on to warn that the independence debate had in the past "too often been marked by rancour and bad temper".