The former Republic of Ireland boss has been backed into 3/1 from 20/1 in the betting.
"We took bets of up to £100 for Kerr this morning at 20/1 from clients in Sheffield and the Republic of Ireland," said Graham Sharpe, spokesman for bookmakers William Hill.
"We shortened him to 14/1 at which price we were accommodated rapidly from customers in Leeds and Ireland.
"Then a female client in Leeds opened an account purely to back Kerr which she did for £100 at 8/1 and a further £50 when other support had pushed his odds down to 9/2."