LONDON (Reuters) -Hedge funds have crowded into debt-fuelled bets on UK government bonds, increasing the potential for instability in the gilts market, a benchmark for borrowing costs in Britain including mortgages, investors and hedge fund sources say. Bank of England chief Andrew Bailey said in February that non-bank institutions like hedge funds "can propagate liquidity stress in core UK financial markets, notably the gilt market". That is partly due to their activity in short-term lending markets, which more than a dozen sources - including portfolio managers, hedge fund executives and a former central banker - described to Reuters.