Scottish Liberal Democrat leader Willie Rennie has said controversial welfare changes aimed at cutting under-occupancy in social housing should be scrapped.
Speaking to the BBC at the start of the party's annual conference in Aberdeen, Mr Rennie said the policy was not working as intended.
"The bedroom tax is tough, I am not a fan of it," he said.
And he added: "I think it should just go, and it should go quickly."
Mr Rennie previously described the changes to housing benefits as "tough", but had not signalled that he was in favour of scrapping the policy altogether.
In a webcast with BBC Scotland's political editor Brian Taylor, who asked questions sent in by the public, the MSP said: "The bedroom tax is tough, I am not a fan of it I have to say, I think we have been working hard to mitigate.
"I have been working with John Swinney and my colleagues at Westminster to make some changes to it. So, we will see what happens in due course."
He added: "I think the bedroom tax, the proposals on it, the principle behind [it] I can understand, but to be honest I don't think it is working as it was intended and I think it should just go, and it should go quickly."
The UK government - a coalition of the Tories and the Liberal Democrats - has argued that the policy, which cuts benefit for social housing tenants deemed to have one or more spare rooms, was needed to free-up accommodation for people living in crowded accommodation.
However, BBC research has shown that only 6% of those affected by the changes had moved home.
Asked why he was in favour of reversing the policy, Mr Rennie added: "You don't get the churn we were trying to get from the proposal.
"I don't think we are managing to mitigate effectively, so I think the whole thing should go."
Following Mr Rennie's comments, UK Liberal Democrat leader and Deputy Prime Minister Nick Clegg signalled that the UK government may agree to Scottish government demands that would effectively end the "tax" in Scotland.
The Scottish government had asked that a cap on payments which can be used by councils to support tenants affected by the housing benefit change be lifted, allowing it to fully mitigate the impact of the policy.
Mr Clegg said: "There are some councils in Scotland who have run up to the limit of the funds they have available to them for discretionary housing payments.
"There is this limit - a cap in effect - on what councils can use which I think needs to be addressed, and we will be making an announcement about that shortly."
In a wide-ranging interview, the Scottish Lib Dem leader also discussed the prospects for further devolution should Scotland vote "No" in the independence referendum on 18 September.
Pressed on whether there would be a single proposal from all three pro-Union parties - Labour, the Conservatives and the Lib Dems - before the referendum, Mr Rennie said it was more important to ensure that pro-independence advocates were included in the process.
He said: "You wouldn't want to have a detailed line-by-line policy commitment in advance of the referendum because this needs to be a fully inclusive process, and we would effectively exclude the Nationalists from that debate.
"I want them to be fully included. If this settlement is going to be sustainable for the longer term they need to be involved in it, so that's why we don't have a line-by-line agreement."
Mr Rennie confirmed that he would stand for election in an independent Scotland - an outcome he described as "a distinct possibility" - and said he would "assist" with negotiations between an independent Scotland and the rest of the UK should there be a "Yes" vote.