The former Watford boss recently joined Roy Hodgson's England coaching staff for Euro 2012 but has not signed on permanently, with compensation still to be agreed
Lewington, who was Hodgson’s assistant during his successful spell at Craven Cottage, was announced as part of the Three Lions backroom team for Euro 2012 at the start of the month.
However, the FA has yet to reach an agreement with the Cottagers to attain the services of the 55-year-old beyond this summer's tournament.
Adrian Bevington, Club England managing director, told reporters: “We are delighted to have Ray for the tournament.
“He has worked with Roy extensively and is an experienced coach.
“He is a Fulham employee so Ray Lewington is with us for the tournament and that is all I can say on it.”
Lewington will work alongside former Manchester United and England full-back Gary Neville, who was appointed as a coach last week.