Rafa Benitez has refused to rule out the possibility he could quit as Newcastle United manager before the end of the season as the tension caused by the club’s failure to make any signings in this transfer window continues to grow.

Benitez no longer has a clause in his contract that would mean he is forced to pay more than £6m in compensation if he resigns and is so frustrated by the lack of progress made in recruitment that he is unable to pledge he will not leave before June.

However, the Spaniard conceded he would still find it extremely difficult to leave Newcastle’s supporters and players in the lurch and still clings on to the hope owner, Mike Ashley, will provide the resources needed to ensure this is the last time he has to worry about a relegation battle on Tyneside.

Newcastle ended the summer transfer window more than £20m in profit – although the fee Fulham agreed for striker Aleksandar Mitrovic will be paid in instalments - Benitez’s refusal to sign a contract extension means Ashley is reluctant to sanction expensive permanent signings.

That has forced the club to concentrate on foreign loan deals, but with just three days of the window remaining, no transfers have gone through.