The Northern Ireland (Date of the Next Assembly Poll) Order 2017
Under section 16B(3) of the Northern Ireland Act 1998 (c. 47), if the offices of First Minister and deputy First Minister become vacant at any time, they are to be filled by applying the process set out in section 16B within a period of seven days. Under section 32(3) of that Act, the Secretary of State must propose a date for the next Assembly election if that period ends without the offices of First Minister and deputy First Minister having been filled. The deputy First Minister resigned at 5pm on 9th January 2017 and the offices were not filled within the seven day period which expired at 5pm on 16th January.