Tony Blair says he will appoint no more than 10 non party-political peers to the Lords in each Parliament.
There are 92 remaining hereditary peers in the Lords
It was also revealed retiring Archbishop of York, David Hope, is to be given a life peerage. He has decided to go back to being a parish priest.
Mr Blair, who made that appointment, has said he will continue to nominate to the Queen up to 10 "distinguished public servants" who were retiring.
He retains the unlimited right to appoint party political peers.
A Lords Commission is responsible for the vast majority non-party political appointments.
A final settlement has yet to be reached on how the reformed House of Lords should be composed and what proportion of people should be elected or appointed.
MPs and peers have failed to agree the way forward and opposition politicians have accused the prime minister of packing the Upper House with his "cronies".
The Most Reverend Hope is expected to sit as a crossbencher or independent in the Lords.
He started his ministry as a curate in Liverpool in 1965 and was appointed Archbishop of York in 1995.