Britain's pro-EU camp regains momentum, lifting shares and pound

By Kylie MacLellan and Jemima Kelly LONDON (Reuters) - The campaign to keep Britain in the European Union appeared to regain the upper hand on Monday, putting the pound on track for its biggest one-day gain in more than seven years and buoying the UK stock market. Sterling rose by as much as 2.4 percent against the dollar on Monday, heading for its biggest one-day rise since December 2008, while Britain's FTSE-100 shares index jumped 3 percent - its biggest one-day gain since mid-February. The k