Ieuan Wyn Jones said it was difficult for him to take the full rise

Mr Jones said he would accept a rise in line with that of public sector workers' pay - an average 2.5% - and give the rest to charity.

Another six Plaid AMs have refused the rise and others among the 15-strong group are considering the matter.

A review by an independent commission concluded the increase reflected the further responsibilities AMs now have.

The rise takes AMs basic salaries to �50,692 a year, 82% what MPs at Westminster earn. But it has been criticised.

The cross-party Assembly Commission argued the rises were inevitable when the assembly had further powers to draft and pass laws.

Mr Jones, also Plaid Cymru's leader, said it was difficult for him to accept such a large rise at a time when public sector pay was being squeezed.

He said he would not accept the full pay award for at least two years.

Mr Jones emphasised that he "respected" the independent review but that the decision to accept or reject the extra money was a personal one for each AM.

"Circumstances are different in each case but I think it's very difficult for me personally to accept an increase over and above what public sector workers are getting," he said.

"Each individual AM will have to speak for themselves," Mr Jones added.

He promised to donate the difference between a 2.5% average increase for public sector workers and the 8.3% awarded to AMs to two charities - Christian Aid and the Stroke Association.

'Effective democracy'

The other six Plaid Cymru AMs who have said they will not take the pay rise are Chris Franks, Alun Ffred Jones, Leanne Wood, Nerys Evans, Bethan Jenkins and Dai Lloyd.

Independent Assembly Member Trish Law has also said she will only take the same rise as public sector workers.

But the assembly's presiding officer and commission chair, Plaid AM Lord Elis-Thomas, has defended the 8.3% increase as "the price of an effective democracy."

No AMs from Labour, the Conservatives or Liberal Democrats have said they will decline the full salary rise.

Labour has already said it would abide by the commission's recommendation and a spokesman said: "We are not making any further comment on this."