Polling in the South Antrim by-election takes place today. The election, described as "too close to call", is being seen as a test of the Good Friday Agreement, with defeat for the incumbent UUP by the DUP providing a boost for hardliners opposed to the peace process. The UUP leader, David Trimble, last night appealed to voters saying: "There is more at stake in this election than in any other in recent times"