Wrexham will miss out on nearly 800 affordable homes as a result of changes to a key housing blueprint, opposition councillors have claimed.
The Local Development Plan (LDP) for 3,400 new homes now expects 505 to be classed as affordable instead of 1,283.
Plaid Cymru members claimed council officers had been pressurised by house builders who would benefit to the tune of millions of pounds.
Chief planning officer Lawrence Isted said developments had to be viable.
Local authorities are required to draw up an LDP to reflect expected housing and business needs, with the Wrexham plan looking ahead to 2028.
Developers are generally asked to make some of the houses they build available as social or affordable housing below market rates, according to the Local Democracy Reporting Service.
The alterations partly follow an assessment by district valuers of the viability of two schemes - on Ruthin Road and Cefn Road - where more than 3,000 houses could be built.
Plaid Cymru councillor Carrie Harper, who represents the Queensway area of Caia Park, said: "Reducing the numbers of affordable homes allocated seriously jeopardises the plan as a whole and the decision seems to have been made as a result of developers putting pressure on officers and councillors.
"Why bother to have a long and detailed planning process if the goalposts can be moved at the very last minute?"
Mr Isted defended the decision, saying: "Whilst any reduction in affordable housing is to be regretted, the council must use the most up to date evidence available when presenting its case to the inspectors who are examining the LDP.
"The aspirations that we have for affordable housing must actually be deliverable and the LDP will have to adapt to reflect evidence of viability as well as of need."
The LDP is being examined in public on Thursday and Friday by independent inspectors who will take the decision as to how the plan, and the policy on affordable housing, is taken forward.