Morning Extra - SNP victory in Glasgow East

What does the SNP's Glasgow East by-election victory mean for Labour? Labour has lost Glasgow East to the SNP in one of the most stunning by-election victories in years. The constituency's new MP John Mason says his victory has sent a clear message to Gordon Brown and Labour at Westminster. Is it just a kicking for The Prime Minister, or are we looking at a much deeper disillusionment with Labour generally? Graham Stewart takes your calls, texts and emails.