The Taoiseach has said the National Asset Management Agency is vital if the country is to avoid years of stagnation or worse.
Mr Cowen was speaking at the close of a special parliamentary party meeting that heard a call for the legislation to be changed to take the Minister for Finance out of the valuation process.
Brian Cowen said any amendments could be considered but stressed that there was no alternative to the establishment of NAMA.
Laois-Offaly TD Sean Fleming made the call for Brian Lenihan to change the valuation process.
Mr Fleming told RTÉ News that he wants to see the involvement of the Minister totally removed from the valuation process.
He said there should be a new process in place to deal with differences over valuations if they arise.
He said that if either the banks or NAMA are unhappy with the valuation, the issue should be resolved in the courts by a commercial Judge.
Under current proposals NAMA sets the value, but if that valuation is disputed by the banks it goes to a valuation panel.
The decision by the valuation panel is then referred to the Minister for Finance.
Mr Fleming also supported a call on party leaders to allow politicians that have lost the party whip to be readmitted to the party.
Fellow back-bencher and Cork East TD Ned O'Keefe said Jimmy Devins, Eamon Scanlon, Jim McDaid and Joe Behan should not be kept outside the party.
Earlier, the Taoiseach said members of the party knew there were tough decisions to be made that will be politically unpopular.
Speaking on RTÉ's Morning Ireland, Mr Cowen said that a job needed to be done to rescue the economy and the Government would have to do it.