Announced on 29 December 2009 she was withdrawing from public life due to bouts of depression. She would vacate her Assembly seat immediately, but would continue as an MP until the 2010 general election. (See Belfast Telegraph article.) It emerged that at a DUP meeting on 9 January, Iris Robinson had her membership of the party terminated (see RTÉ article). This means in effect the whip was withdrawn from her. She was expected to stand down from both Stormont and Westminister, although as a UK general election must be held by early June, there is not expected to be a by election for her Strangford seat. Provisions exist for the replacement of MLAs without requiring a popular vote.
On 13 January 2010, Iris Robinson was appointed to be Steward and Bailiff of the Three Hundreds of Chiltern, which requires her to relinquish her seat in the House of Commons with immediate effect. She is the first Northern Ireland MP to resign since the mass resignation of Unionist MPs in protest at the Anglo Irish agreement on 17 December 1985. She resigned from the Northern Ireland Assembly on the same day, but remains a councillor on Castlereagh Borough Council.