One of the candidates to become the new leader of Scottish Labour has expressed "reservations" about the full devolution of income tax powers to Holyrood.

Sarah Boyack said her reservation centred around the pooling and sharing of resources within the UK.

A fellow challenger for the post, Neil Findlay, said care must be taken to make sure Scotland does not end up worse off as a consequence of any changes.

Ms Boyack, Mr Findlay and third candidate Jim Murphy spoke to BBC Scotland in the wake of reports that the Labour Party is to abandon its opposition to handing full control of income tax to the Scottish Parliament.

The reported move comes as the Smith Commission, the body looking at more powers for Holyrood in the wake of the Scottish independence referendum, prepares to publish its recommendations this week.

Labour had backed giving Edinburgh control of three-quarters of the basic rate of income tax amid concern that full tax powers could weaken Scottish MPs at Westminster and pave way for the UK Government to cut the Scottish Government's budget.

But reports in today's Sunday Times Scotland and Scotland on Sunday suggested that with the Conservatives, Liberal Democrats and SNP favouring more far-reaching reform on the issue, Labour's negotiators are conceding that they too will have to go further.

When the commission's work is published on Thursday, it is expected to recommend full devolution of income tax rates and bands, reports said.

Asked whether Labour should be pursuing this new stance, Ms Boyack told BBC Scotland: "I, amongst many others, have got reservations about the full devolution of income tax. I think we need to look at a wide range of taxes."

She told the Sunday Politics Scotland programme her reservation centred around the "pooling and sharing of resources".

But she added that the commission should be allowed to get on with its work.

The Lothian MSP said: "There's a whole raft of different tax policies.

"The Scottish Parliament needs to become more accountable for the money we raise as well as how we spend that money.

"I think at this point I would far rather let the Smith Commission work their way through the whole range of issues they've got to look at."

Mr Findlay, Labour's Holyrood health spokesman, urged caution, saying: "I think we have to be careful because what we don't want is a deal that ends up with Scotland being worse off.

"That's the principle that I would apply to the whole negotiations in the Smith Commission."

He added that speculation on the commission's findings was "not helpful".

He told the show: "Let's just see what happens out of the Smith Commission. Let's not pre-empt what happens."

Former Scottish secretary Jim Murphy said: "I look forward to what Smith comes forward with but we really have to test it against 'Is it good or bad for Scotland?'."

He told the programme: "We have to understand the anger of many of the Yes voters who were desperate for change. Not all the Yes voters want independence.

"A lot of them were just scunnered, frustrated, with the status quo and wanted change, so we have to deliver the change."