What does SNP success mean for Plaid at Westminster?

Plaid Cymru MPs Hywel Williams, Jonathan Edwards and Liz Saville Roberts

While the Labour and the Liberal Democrat leadership elections continue, Plaid Cymru have announced their new leader at Westminster.

It's Jonathan Edwards, the MP for Carmarthen East and Dinefwr. He replaces Elfyn Llwyd, who stood down at the election.

It had been expected that Mr Llwyd would be replaced by Arfon MP Hywel Williams, but he decided to pass on the opportunity for family reasons.

Mr Edwards had previously been resistant to the idea in case it cramped his political style but has now been persuaded to take the leadership path.

He has identified three themes for the next five years at Westminster: "The Human Rights Act, a European Referendum and the political autonomy of the nations within the British state will be some of the defining issues of this Parliament. They have the ingredients to ignite major constitutional battles and will undoubtedly impact upon the daily lives of our people, our businesses and our communities."

Getting the collective voice of three MPs heard in a House of Commons of 650 members will, as ever, be a challenge, although Mr Edwards argues that Plaid's MPs have always punched above their weight.

The success of the SNP may, counter-intuitively, make that challenge more difficult. In the last parliament, Plaid and the SNP were treated as a single official group. They were on the same "rota" for prime minister's questions. With 56 SNP MPs and only three Plaid members, another joint group would look rather lop-sided.

Instead, the SNP are likely to meet as a single group, although they and Plaid are expected to work together with joint meetings held at leader level - involving Angus Robertson, Jonathan Edwards and Green MP Caroline Lucas.

The SNP have been swift to claim "third party status" at Westminster, taking over the Liberal Democrats' whips' office and expecting to be able to ask two questions of the prime minister every Wednesday. Plaid may find themselves on a PMQs rota of smaller parties denied the status offered to their sister party from Scotland.

You can read the full Plaid Cymru press release on Jonathan Edwards's appointment here. You can watch Elfyn Llwyd's advice to new MPs here (with a cameo contribution from his pigeons).

Update: In a joint statement the three parties have said they will unite "whenever possible" at Westminster to oppose austerity.