The family of Welsh politician Carl Sargeant would be given “a real slap in the face” if departing First Minister Carwyn Jones was awarded a peerage, according to Mr Sargeant’s son.

Jack Sargeant said Labour leader Jeremy Corbyn should not nominate Mr Jones for a seat in the House of Lords while questions surrounding his father’s death remained unanswered.

The First Minister will tender his resignation to the Queen following his final questions session on Tuesday afternoon, bringing an end to nine years in power and making way for new Welsh Labour leader Mark Drakeford to take his place.

Despite delivering Welsh Labour’s best election result in 2011, Mr Jones’s reign has ended with him under fire for his conduct towards Mr Sargeant, who was found hanged at his home four days after being sacked amid allegations of sexual misconduct in November last year.

Mr Sargeant’s son Jack, who succeeded him as AM for Alyn and Deeside following a by-election in February, said speculation that Mr Jones could be given a peerage after leaving the Welsh Government was “distressing”.

He said: “Nothing could be more distressing for the family and friends of Carl to know that such an accolade could be bestowed when there are so many unanswered questions regarding the First Minister’s conduct.

“It would be a real slap in the face to those of us already suffering Carl’s loss. If Jeremy Corbyn gives the nod to Carwyn Jones to go into the House of Lords, we will be distraught.”

He also said he felt his father’s inquest has been subjected to “unnecessary delaying tactics” by the First Minister’s office, and questioned whether there was a plan “to ensure he was out of office before the inquest concluded”.

The inquest into Mr Sargeant’s death has been adjourned indefinitely for Mr Jones to be recalled as a witness and to allow a legal challenge by his representatives.

Leighton Andrews, a former minister for education and skills in Mr Jones’s cabinet, said unresolved issues over Mr Jones’s handling of the allegations against Mr Sargeant before his death could taint his legacy as First Minister.

Mr Andrews, professor of practice in public service leadership and innovation at Cardiff University, said: “The difficulty for him is that at the point he leaves, all of these issues of sacking Carl Sargeant remain unresolved.

“I think it’s cast a shadow over his time in office and over his departure from the government.”

Mr Jones’s nine-year stint leading Wales saw him guiding the country into an era where its Assembly now has lawmaking and tax-raising powers for the first time. He led Welsh Labour to its best election result in 2011, two years after he took up the position.

He took the decision for the Welsh government to purchase the under-performing Cardiff Airport, which has since seen a rise in passenger numbers and improved facilities, passed the Human Transportation Act, which brought in the “opt-out” organ donation system, and was the first leader in the UK to bring in a levy on plastic bags.

Professor Roger Awan-Scully, head of politics and international relations at Cardiff University, said: “Electorally, Carwyn Jones has been a giant.

“Even last year in the general election when Labour was really up against it, he took control of the Labour campaign in Wales front and centre, really risked everything, and of course Labour came out with a really good result in Wales, gaining several seats away from the Conservatives.

“I think electorally his party may only really fully value him when he’s gone.”

But he said critics would argue Mr Jones’s popularity with the public failed to translate into success with key public services.

“I think the key questions of his legacy are in terms of public policy. Has he delivered enough improvement in Wales in terms of economic performance, has he been able to deliver real and sustainable improvements in key public services that are devolved, such as health and education, and people will argue that backwards and forwards.

“His critics will say, though he was popular electorally, he didn’t do enough with that in government.”