David Cameron could be hauled in front of MPs to explain his resignation honours list after the chair of a Commons committee called for an investigation into the controversy.
The former prime minister was accused of cronyism after he dished out gongs to a string of political allies, Tory donors and Downing Street staff.
Bernard Jenkin, chair of the Public Administration and Constitutional Affairs Committee, has invited its members to probe Mr Cameron's resignation honours and his nomination of 13 new peers when Parliament reconvenes in September.
The cross-party group of MPs could summon the ex-PM as a witness and subject him to a public grilling as part of any inquiry.
In 2012, the committee recommended that a "far higher proportion" of honours should be awarded to "people who devote their time to the local community, instead of to politicians, civil servants, and celebrities".
Its report expressed concerns that political considerations influence the awarding of honours and recommended that the process should be independent of the PM, but this was rejected by the coalition government.
Calling for a new inquiry, Mr Jenkin said: "We have already discussed the principle of holding an inquiry into the House of Lords.
"This should include the size and composition of the House of Lords, but also the way in which new peers are appointed.
"I think reform of the House of Lords is by far the most important issue arising from this month's controversy.
"I hope the new Government will consider this and our previous report seriously, and I hope the committee will agree terms of reference and to launch our inquiry as soon as the House returns in September."
Following the row over Mr Cameron's list, Labour offered to co-operate with the Government in rushing through emergency legislation to stop prime ministers handing out honours on leaving office.
It came after the chairman of the Committee on Standards in Public Life, Lord Bew, said the list of 59 Cameron nominations for peerages and gongs "has to be the last one, given the public outcry".
In his resignation honours, Mr Cameron created 13 Tory life peers, giving the Tories 207 - one more than Labour.
Tory treasurer Andrew Fraser, and political aides Gabrielle Bertin and Camilla Cavendish, who both worked at Number 10, were all given peerages.
Knighthoods were given to Cabinet ministers Michael Fallon and Patrick McLoughlin and former ministers Oliver Letwin and Hugo Swire, while former chancellor George Osborne became a Companion of Honour.
Notable by their absence were former Conservative treasurer Michael Spencer, whose nomination for a peerage was reportedly blocked by an independent advisory committee, and Tory donor Ian Taylor, who asked for his name to be withdrawn after negative publicity.
Samantha Cameron's stylist Isabel Spearman received an OBE for political and public service.
There were awards, too, for Mr Osborne's aides, including OBEs for chief of staff Thea Rogers and her deputy Eleanor Wolfson, and an MBE for his constituency manager Jane Robertson.
And key campaigners in the EU referendum were also rewarded, with a knighthood for Andrew Cook, the treasurer of Conservatives In, and a CBE for Stronger In campaign director Will Straw.