Crystal Palace are locked in talks with Peterborough United for Ronnie Edwards.
The England U21 defender has been the subject of multiple offers from Palace this season.
The London Evening Standard says Palace have made three offers for Edwards, with talks continuing. Among the stumbling blocks is the size of an agreed sell-on clause.
Posh are also making a loan demand for this month.
Peterborough director of football Barry Fry and chairman Darragh MacAnthony are demanding Edwards be loaned back to the League One promotion contenders until the end of the season.
Former club Barnet will be due 50 per cent of any fee raised from Edwards' sale.