Theresa May has appointed nine new Conservative members of the House of Lords and handed another peerage to her DUP allies.

Jeremy Corbyn has also given seats in the Lords to former Labour general secretary Iain McNicol and veteran anti-racism campaigner Martha Osamor.

With 244 members of the Lords, the Conservatives Party has the most peers.

However the government does not have a majority in the 780 member chamber and has suffered a series of damaging defeats on its Brexit legislation over the past few weeks.

The new appointments will not shift balance in a significant way however, as pro-Remain Tory peers have repeatedly rebelled against the prime minister on her EU legislation.

Darren Hughes, Chief Executive of the Electoral Reform Society, said the creation of new peers was an “insult to voters”.

“This has now gone beyond a joke. Time and time again the government talk about reducing the cost of politics. Yet at the same time they’re packing the upper house with former MPs and retired party hacks,” he said.

“If Mrs May was serious about reducing the cost of politics, she would halt these appointments rather than providing yet more fuel for public concern about cronyism. It is an insult to voters.

“Furthermore, the timing of the announcement appears deeply cynical. At the beginning of the year the Prime Minister lost her nerve in the face of public opposition and delayed making the announcement. Now she is expected to try and hide it behind the euphoria of a Royal wedding.”

In full: the 13 new peers

For the Conservative party, they are:

Diana Barran MBE – founder and lately chief executive of SafeLives, 

Sir Edward Garnier QC,

Sir Alan Haselhurst, former deputy speaker of the House of Commons,

Peter Lilley, former secretary of state for social security, 

Catherine Meyer, founder and lately chief executive of Action Against Abduction, 

Sir Eric Pickles, former secretary of state for communities and local government,

Sir John Randall former deputy chief whip, 

Amanda Sater, former deputy chairman of the Conservative Party, 

Andrew Tyrie, former chairman of the Treasury Select Committee.

For Labour, they are: 

Martha Osamor, campaigner on immigration, employment rights and racial discrimination, 

Pauline Bryan, author and campaigner, 

Iain McNicol, former general secretary of the Labour Party.

For the Democratic Unionist Party, Dr William McCrea, former MP for South Antrim.

Lord Fowler, the Lord Speaker, said: “When the Prime Minister wrote to me in February, she made it clear that the new peerages announced today are a long-planned list arising from the dissolution of Parliament before the June 2017 general election.

“In that letter, she also committed herself to restraint when making new appointments to the House of Lords. The relatively modest size of today’s list when compared with those under several previous Prime Ministers has demonstrated a welcome commitment to that pledge.

“I established a committee under the chairmanship of Lord Burns to reduce the size of the House which reported last October. Their report was supported by the House of Lords itself.

“Today’s appointments in no way undermine those recommendations: indeed, the number of new peers announced today is about a third of the 35 peers who have left the House since the 2017 election. The size of the House is falling, and our aim is to continue that progress.”