The National Pensioners' Convention, which has 1.5 million affiliated members, and Help the Aged are to write to Sir Gordon Borrie, chairman of the commission, protesting that the report does 'precious little' for the estimated 3 million pensioners living on or below the poverty line.
They claim a guaranteed minimum pension, above the state pension and income support, would not lift pensioners out of poverty unless it was increased substantially.
And they fear that the suggestions that more pensioners and their families should pay for their own long-term care will impoverish older people for at least the next two decades. They argue that the proposal for younger generations to take out compulsory long- term care insurance will do nothing for people now aged 65 or more.
Jack Thain, secretary of the National Pensioners' Convention, said he had written to Sir Gordon complaining that the group had not even been consulted by the commission.
He said: 'Our generation is fast fading away and many will not see the early 21st century. Everyone seems to be planning for 2010 and beyond . . . They are trying to ignore us.'
Age Concern is also disappointed that the commission has departed from the Labour Party's election pledge that the state pension would be increased and uprated in line with earnings.
Both groups have estimated that retired people need a pension of pounds 100 a week for a single person and pounds 160 for a couple - equivalent to one-third of average earnings for a single pensioner and half of average earnings for a couple - for a decent standard of living.
The state pension is now pounds 57.60 for a single person and pounds 92 for a couple and income support ranges from pounds 63.95 to pounds 70.40 for a single pensioner to pounds 99.25 to pounds 107 for a couple.
Andrew Dilnot, director of the independent Institute of Fiscal Studies, said the most striking thing on pensions in the report was the proposal to allow the state pension to 'wither away' and at best to increase it in line with prices.
Jeremy Corbyn, MP for Islington North, said he was 'very worried by the commission distancing itself from the universal benefits of the basic state pension and child benefit.'
Frank Field, MP for Birkenhead, felt the report was not radical enough. 'I hope it is going to break the log-jam in that people will now feel free to say what they believe should be done about benefits and the welfare state, rather than what they think others believe they should say.'