Prime Minister and land of his great-great-grandfathers

He may describe himself as "an English lad" but David Cameron is qualified to play for Wales.

The prime minister hosted a Downing Street reception to mark St David's Day this evening with a speech reflecting on his Welsh ancestors.

"I've been doing some research into my relatives. My grandmother on my mother's side was a Llewellyn and I went a little bit further back and I found that her grandfather was actually called Llewellyn Llewellyn. He was a tinplate maker in Glamorgan."

With a nod perhaps to recent speculation about the leadership ambitions of Stephen Crabb, Mr Cameron added: "This does not mean I want to be Welsh Secretary in your government Stephen...but I think that's real Welsh heritage."

As is traditional on these occasions, Welsh food and drink was consumed, a choir sang and Welsh celebrities mingled with business people and politicians.

As is also traditional on St David's Day, the politicians discussed constitutional reform.

'Exciting'

The prime minister told his audience: "I think it was exciting what was agreed between all political parties - and it's great to see different political parties in our country represented here tonight - but what was agreed in the St David's Day process - to have a stronger Welsh parliament, a parliament that has not just the ability to spend money but also the responsibility of raising money with a whole fresh set of powers.

"Because what I want passionately to happen is for the United Kingdom to make sure there's genuine respect between the parliaments of the United Kingdom, between the different governments of the United Kingdom, devolution settlements that work for everyone whether you're in Wales or in Scotland, in Northern Ireland or indeed in England."

Exciting or not, there are already tensions between the UK and Welsh governments over last week's agreement. Stephen Crabb has written to Carwyn Jones tonight to warn of that momentum could be lost unless he backs the deal.

Mr Jones believes the deal isn't clear enough about the future funding of his government. Mr Crabb says the funding plan is exactly what the Welsh government asked for. There may be trouble ahead.