you will find that one off two thing has happened, 1 the washer needs changeing and has got stuck, (change washer) or two the spindle is broken, ( NEEDS NEW SPINDLE, YOU NEED TO TURN HOT AND COLD WATER OFF, AND UNSCREW THE TAP HANDLES, THEN THE SPINDLE, LOOK AND SEE IF THE TAP WASHER IS ON THE UNDERSIDE OF THE SPINDLE, IF NOT ITS THE WASHER, LOOK INSIDE THE ATP FOR IT AND REMOVE, IFD IT IS THERE YOU NEED A NEW SPINDLE, KEEP THE WATER OF AND SOMEWHERE LIKE B&Q WILL HAVE ONE TAKE IT WITH YOU. GOOD LUCK
BIG JOHN, May 2006