In a written response to Labour MP Baroness Hollis, Lord McKenzie of Luton produced figures showing that individuals in these categories would only see returns of between 1 and 3 per cent greater than if they did not save in the scheme.
The figures are calculated for workers who do not already have private pensions and who would be saving at the default rate.
Hargreaves Lansdown head of pension research Tom McPhail says the figures show those who can afford to save should look at other options.
He says: “They are asking people to save 4 per cent of their income for 10 to 20 years in order to be 1 per cent better off in retirement. I think the Government will struggle to sell that to people.
“Some people will be better off in a savings gateway, some in an Isa, some in a pension and others down at the pub. It will be extremely challenging for the Government and the pension industry to decide which category people belong to.”
A Department for Work and Pensions spokesman says whether another product would be more suitable than a personal account would depend on individual circumstances.
He says: “What we want is for people to save for retirement and that is the main thing that the pension reforms aim to do.”