<text>  A petty feud between the two most powerful women in Ed Milibands inner circle has rocked the Labour Party. The dispute between the partys Election chief Lucy Powell and Chief Whip Rosie Winterton flared up over an invitation to the Brit pop music awards on the night of a crucial Commons vote. Insiders say the row brought simmering tensions between the starkly contrasting pair both rivals for Milibands ear to a head. Flare-up: Election chief Lucy Powell, 40, left, and Chief Whip Rosie Winterton, 56, became embroiled in a dispute over Ms Powells Brit Awards plans . It was caused by the desire of 40-year-old Ms Powell who is tipped as a future Labour leader to attend the Brits pre-party where guests mingle with pop stars. But Ms Winterton, 56, ordered Ms Powell to stay at Westminster for a vote called by Miliband to ban MPs having second jobs. One source said: Rosie told her she had no right to miss the vote to go hobnobbing with Madonna and Co. The argument reportedly intensified when Powell was told she had a special duty to be there because the second jobs debate was partly the responsibility of Labours Shadow Cabinet Office team, which includes her. In the end, Ms Powell backed down and took part in the vote. But she still managed to get to the main Brits Awards event at Londons O2 Arena. Yorkshire-born Ms Winterton, who has never married and is renowned for her black leather boots, revels in her role in charge of party discipline. Commenting on the dispute, one source said: Rosie told her she had no right to miss the vote to go hobnobbing with Madonna pictured falling on stage and Co at the Brits . She learned her backroom wheeler-dealing skills from her mentor and close friend John Prescott, who gave her first break in politics as tea girl in his office in 1980. Stylish Lancashire-born brunette Ms Powell has had a meteoric rise through the partys ranks. Only two years after becoming an MP, Miliband put her in charge of his Election campaign in November. A Labour MP said: Lucy and Rosie are a generation apart and totally different in their approach to politics. We have been waiting for this dust- up to occur. A Labour spokesman said last night: There is no truth in this allegation. 