Exactly 20 years since the day that Welsh voters elected the first National Assembly, a poll for the S4C politics programme 'Y Byd yn ei Le' reveals that doubts remain about how much devolution has achieved.

On the Assembly's key task of holding the government to account, only a third of voters (34%) are positive that it's doing better than when Wales was run by a Welsh Office answerable to Westminster. A quarter (25%) are certain that it hasn't improved how Wales is governed.

But the poll also showed that few Welsh voters want to go back to not having an Assembly, just over a half would either give it more powers (27%) or keep it as it is (25%).

Giving the Assembly more powers is the most popular option. Credit: S4C 'Y BYD YN EI LE'

There remain 15% who would simply abolish the Assembly whilst 12% would prefer Wales to leave the UK and become independent.

Most voters think that the National Assembly should have the same powers as the Scottish Parliament. Credit: S4C 'Y BYD YN EI LE'

There's even stronger support for increasing the Assembly's powers if the issue is seen as whether Wales should get equal treatment with Scotland. That would involve substantial further devolution, notably in the fields of policing and justice.

In terms of the Assembly's existing powers, one of the greatest doubts about what's been achieved concerns the NHS.

Less than a quarter of Welsh voters think that having an Assembly has improved the NHS? Credit: S4C 'Y BYD YN EI LE'

Health consumes roughly half of the Welsh Government's £16 billion budget so AMs success or otherwise in getting the right results is a crucial test but 29% of voters think that the NHS has got worse since devolution.

The poll has thrown up plenty of other points for AMs to ponder. 53% think the at Assembly is too Cardiff focussed and 44% that it costs too much. 43% think that the Assembly is too dominated by the Labour party, though of course the whole point of having an Assembly is that it's voters in an election who decide who holds political power.