It was confirmed earlier this week that a fee had been agreed between the two clubs however there now appears to be an issue regarding personal terms with them yet to having been agreed.
Maddison was given permission by Posh to speak with Charlton however discussions between the Championship side and Maddison are not running smoothly.
The offer that has been put on the table by the Addicks is a long way from being agreed by the midfielder and this is something they are yet to resolve which could pave the way for other clubs to swoop in for Maddison.
Peterborough owner Darragh MacAnthony claimed that he rejected multiple offers from other Championship sides for Maddison before accepting the bid from Lee Bowyer’s side.
Birmingham City were said to have made two bids for the playmaker and West Bromwich Albion were also believed to be interested in the League One player.
The League One promotion hopefuls are prepared to cash in on their star man this month rather than risk allowing him to run down his contract with it expiring in the summer.
He has a £2.5million release clause in his contract which is also attracting potential suitors from clubs higher up in the football pyramid.
If Charlton are unable to reach an agreement with Maddison he could decide to see out his contract and leave on a free transfer at the end of the season or Peterborough could seek to consider offers from other clubs.