The Bradford South MP was speaking after police recovered the remains of Suzanne Blamires and Shelley Armitage from the River Aire.

BBC: Gerry Sutcliffe

The Conservatives had originally won the seat in 1983 from Mrs Cryer's late husband Bob, who died in 1994 in a car crash whilst serving as MP for Bradford South.

BBC: NEWS | VOTE 2001 | RESULTS & CONSTITUENCIES | Keighley

There have been 12 by-elections in England and Scotland since the start of the current Parliament - Oldham and Saddleworth, Barnsley Central, Leicester South, Inverclyde, Feltham and Heston, Bradford West, Corby, Manchester Central, Cardiff South and Penarth, Rotherham, Middlesbrough and Croydon North.

BBC: Voting nearing an end in Eastleigh by-election