 After his re-election to the Northern Ireland Assembly, Maskey announced on 12 May 2011 that he would be standing for selection as Sinn Féin candidate for the Belfast West constituency in the House of Commons of the United Kingdom, which had been left vacant when Sinn Féin President Gerry Adams resigned to fight for a seat in Dáil Éireann.He was immediately supported by Gerry Kelly MLA.and as the only nomination for the vacancy, was selected on 19 May.