Scotland election battle 'wide open'

Labour is vowing to "fight every step of the way" in Scotland despite polling suggesting the party could face a near wipe-out at the hands of the Scottish National Party.

If the results of eight constituency-level surveys carried out by Conservative peer, Lord Ashcroft, were mirrored at the general election, they would seriously jeopardise Labour's chances of a majority at Westminster.

The BBC's Scotland correspondent James Cook analyses the potential implications for the UK as a whole.