George Galloway scored Friday a dramatic victory in the Bradford West parliamentary by-election, northern England, securing a 10,000-plus majority in what he called a \"massive rejection\" of mainstream parties. His small party \"Respect\" swept from fifth place at the 2010 general election to a commanding victory for the ex-Labour controversial anti-war campaigner against his former party on a swing of 36.59 percent. It was \"the most sensational result in British by-election history bar none\", he said on stage after being declared the victor with well over half the total votes. The reverse is a serious blow for the opposition Labour which entered polling day as overwhelming favourite to retain the seat at the end of a fraught week for the Government, commentators said. Instead, it became the first Opposition party to slump to defeat in a mid-term poll since the Liberal Democrats took Romsey seat in England from the Conservatives in 2000. Party sources pointed to a massive slump in the Conservative vote as evidence of the Government\'s unpopularity. The Liberal Democrats lost their deposit. However, the scale of the turnaround, in a seat the party had held since 1974, is bound to raise further questions about the leadership of Labour leader Ed Miliband, the commentators noted. Galloway won 18,341 votes to the 8,201 for Labour candidate Imran Hussain. Labour went into the contest - sparked by the resignation due to ill-health of Marsha Singh. Galloway targeted the votes of a large Asian community in the area. He told Sky News he had won a \"big victory\" - winning at least 50 percent of the vote in some areas and doing well in areas without large Muslim populations. There were congratulations for Galloway from Labour MP Jeremy Corbyn who, like his former party colleague, has been a strong opponent of the Iraqi and Afghan campaigns.