City have offered the player a new deal, but the lure of league football might be too much for the former Hull City trainee to turn down.
Peterbrough director of football Barry Fry has confirmed that he will be doing everything within his power to secure the hitman's signature.
"We've offered a good sum of money for Clayton, but York are not keen to let him go," Fry told the York Evening Press.
"He's out of contract in the summer and we could go to a tribunal and get him a lot cheaper then.
"But we're in a position where we want to go up and we want to have him on board as soon as possible."
York have released a statement confirming that club's have expressed their interested in the striker, but have not received any offers as of yet.
With thanks to www.confguide.co.uk
Source: http://www.confguide.com/newsArticle.do?id=5117