Wales will be worst hit by NHS cuts across the UK, the report by chief economist Professor John Appleby found.
GPC Wales chairman Dr David Bailey said spending cuts would inevitably hit GPs. 'GPs are the gatekeepers of the NHS. Unfortunately when there is more stress on health care, GPs act like a sponge and absorb the extra work,' he said.
Dr Bailey said GPs would have to deal with patients waiting longer to be seen by secondary care.
Professor Appleby said cuts to spending were likely to lead to a reduced quality of care for patients. 'Operations are going to have to cost less and people will have to work harder.'
By 2013/14, the NHS budget in Wales will be cut by 8.3% in real terms. Northern Ireland will face a 2.2% cut by 2014/15.
In Scotland the budget will fall by 3.3% this year, but figures for following years are unknown. In England, the NHS budget will fall by 0.9% in real terms.
A DoH spokesman stressed that the spending review announced increases in the English NHS budget, with a rise by £11.5bn over the next four years.