The council wants to build a brand new leisure centre on the land which was once home to St Mary's Girls School - but the councils says it was told by the parish last week that its offer was unacceptable.The three acre site has been unused since the school relocated in September 2012.It is owned by the parish of Maghera which is part of the diocese of Down and Connor.Down District Council said that it made an agreement on the purchase of the land last October and that contracts were being drawn up.However, the council said that it received notification from the parish's solicitor on Friday saying the offer was "unacceptable".Councillors in Newcastle claim that agreement was reached to buy the site for £500k, but now they're alleging the church is considering an alternative bid worth £750k.One South Down MLA has written to the bishop asking him to intervene.The SDLP's Seán Rodgers said: "I just hope that the Bishops and the church would see the sense of how this would be a win, win for the church, a great community facility for all."For our young children, for our older people and so on."In a statement issued by the Maghera Parish to UTV on Monday evening, a spokesman said: "Following the decline of a private treaty sale in 2012 by Down District Council, the parish Trustees placed the former St Mary's Girls Primary School site at Shanslieve Drive in Newcastle on the public market on 26 March 2013. The agents for the sale were J. D. Flynn and Co., Newcastle."The statement continued saying that offers were received from a number of parties, including Down District Council."The site is held in stewardship for the good of the parish. The parish Trustees are legally bound to act in the best interests of the parish and to consider all offers made through the public market process."In the case of sales of former school sites, the Trustees are required to return a substantial percentage of the final sale price to DENI (Department of Education in Northern Ireland)."The Trustees of the Parish remain open to consideration of Down District Council's offer in regard to the sale of this site."Down District Council said that it is taking legal advice on the matter, which will be discussed at its next full meeting later this month.