When John McCallister resigned from the Ulster Unionist Party on 14 February he accused the party leader, Mike Nesbitt, of ‘forcing Northern Ireland politics back into the sectarian trenches’. Hours earlier, the UUP, the Democratic Unionists and the anti-St Andrews Agreement Traditional Unionist Voice had announced that a Unionist unity candidate, Nigel Lutton, would stand in tomorrow’s Mid-Ulster by-election. Martin McGuinness resigned the seat at the end of last year; the Sinn Féin candidate to replace him is the deputy speaker of the Northern Ireland Assembly, Francie Molloy. In 2007, the DUP MP David Simpson, speaking under Parliamentary privilege, claimed that Molloy was involved in the IRA murder of Lutton’s father in 1979. Molloy denies the allegations. The Unionist candidate’s uncle, Joey Lutton, was jailed for his part in a 1976 Ulster Volunteer Force murder.