|Oldham E & Saddleworth by-election betting||LABOUR||LIB DEMS||TORIES|
From what I can see there are five current betting markets on the Old & Sad by election that takes place on January 13th. Labour is the heavy odds-on favourite in all of them though there is some variation.
Be warned – getting bets of a reasonable size on might be difficult. The two exchanges, Smarkets and Betfair, have very little liquidity while the traditional bookmakers might place tight restrictions on what you can bet.