LONDON - Northern Ireland's former leader has called on his successor, Peter Robinson, to step down after the revelation that his wife had an affair with a teenager.

Former Northern Ireland First Minister David Trimble said Sunday that Robinson would probably leave office within days.

The admission by Robinson's wife, Iris, that she had an affair with a 19-year-old when she was 58 has angered many in the couple's socially conservative Protestant constituency.

Robinson's resignation could jeopardize the future of the province's fragile interfaith coalition government.

Trimble led his Protestant Ulster Unionist Party to a peace deal with the province's Catholics, but was trounced by Robinson's hard-line Democratic Unionist Party in 2003.