The Labour Party yesterday demanded an apology from the SNP after one of its MPs strayed into a neighbouring constituency and claimed he was representing it.

The Labour Party yesterday demanded an apology from the SNP after one of its MPs strayed into a neighbouring constituency and claimed he was representing it.

The row broke after newsletters from Glasgow East MP John Mason were delivered in Glasgow North East, where a hotly-contested by-election is about to be fought after the resignation of Michael Martin.

The glossy leaflet, titled "John Mason working for you" and claiming he is "your MP", was delivered to addresses in Dennistoun that are not in his constituency.

One of the newsletters was received by Labour councillor Elaine MacDougall, who said: "I couldn't believe it. My whole street had this leaflet delivered.

"John Mason is pretending to be the MP here, when we're not even on the boundary let alone in his seat.

"Local people don't know if it is just bungling incompetence or something much more sinister."

A Labour spokesperson said: "We take a very dim view of this and we have written to the SNP to ask them to clarify whether this is a deliberate strategy or merely incompetence. Either way, they must apologise and cease these underhand tactics immediately."

A spokesperson for Mr Mason said the newsletter was distributed through a Royal Mail system, which should have ensured it was only received in the constituency.

She added: "Because the delivery is done on a postcode basis there is a possibility that a very minimal amount of leaflets could end up being delivered over the boundary. Mr Mason will be in contact with Royal Mail to ensure the possibility of distribution over boundaries is minimised."

It emerged last night there will be three candidates on the SNP shortlist for the Glasgow North East seat - city councillor James Dornan, David Kerr and Aileen McLeod.