Williams: Lib Dems 'can learn Plaid's coalition lesson'
The Liberal Democrats should learn from Plaid Cymru's experience as a junior partner in a coalition government, the party's leader in Wales has said.
Kirsty Williams said the Lib Dems had to show they are making a difference by sharing power with the Conservatives.
But she attacked Welsh Secretary Cheryl Gillan from the conference platform, saying the Tories' understanding of devolution was shallow.
Mrs Gillan was said to be "baffled and disappointed" by the comments.
Telling the Lib Dem conference in Birmingham she was "no fan of the Tories", Mrs Williams said forming the Westminster coalition last year was "tough" but the "right decision".
She cited the example of Plaid Cymru who suffered at May's assembly election after serving in a coalition government in Cardiff Bay with Labour for four years.
"For me it is clear. The smaller party in government has to be able to show it has made a difference," she said.
"We must continue to remind people that allowing the Conservatives to govern unhindered was no choice at all."
The Lib Dems had to proclaim their achievements, she said, adding: "If the Lib Dem brand has become tarnished then disowning that brand isn't the answer."
As part of its coalition agreement, the UK government has promised a commission to examine how Wales is funded.
But Mrs Williams said it was up to Lib Dems to "push forward radical reform" because the Conservatives' understanding of devolution is "too shallow".
"Do you think we can rely on a Conservative Secretary of State to deliver?" she said.
The Welsh Lib Dem leader said Deputy Prime Minister Nick Clegg and Chief Secretary to the Treasury Danny Alexander were "pushing the case for Wales", adding: "Well, Cheryl, somebody's got to do it."
She said the Conservative Welsh Secretary's accountability to the people of Wales was "tenuous" and that the Wales Office did not believe in giving away power.
A UK Government spokesman said Ms Gillan had delivered a referendum on the assembly's law-making powers and had involved Mrs Williams in decisions. She was said to be "baffled and disappointed" by the attack.
The source said: "Such a personal attack on Cheryl is very regrettable.
"What Kirsty said does not stand up to scrutiny.
"Her comments are not going to do anything to improve relations between the Wales Office and the Welsh Liberal Democrats."
Mr Clegg, who is also due to address the final day of the conference in Birmingham on Wednesday, has said the coalition with the Tories in Westminster was partly to blame for a poor showing by his party at May's assembly elections.
The Lib Dems have endured a difficult year in Wales, losing a seat in the assembly and seeing their share of the vote slump with 17 candidates losing their deposits.
Mrs Williams' speech also contained a stinging attack on a Labour's "miserable" record in Wales.
"Labour uses the language of equality. But the poor services they provide do poor people down," she said.
She said: "Unlike most families and businesses, the Welsh Government has the luxury of spending money handed out by others.
"Like the wayward teenager, left school, still living at home. Frittering money away, but complaining that the regular handouts are too stingy."
With half the seats in the assembly, Carwyn Jones's Labour government will need the approval of opposition AMs to get its budget passed.
Mrs Williams said the Lib Dems would not support the Welsh Government's spending plans - a draft budget is due next month - without progress towards closing a funding gap between schools in England and Wales, starting with help for the poorest children.
Earlier, Welsh Lib Dem peer and former AM Baroness Randerson told BBC Radio Wales there was widespread backing for the party leadership and its role in the UK coalition.
"Back a few months ago we were in single figures in the poles," she added.
"I think the public are beginning to recognise the size of the problems left behind by Labour that we are having to grapple with."
A Welsh Labour spokesman said: "Frankly Kirsty Williams' comments make the Welsh Liberal Democrats look ridiculous. They have chosen to form a coalition with the Conservatives and this personal attack sounds very immature."