Image caption Ruth Davidson said her detailed plans would be announced before the independence referendum

Scottish Conservative leader Ruth Davidson has supported more financial powers for the Scottish Parliament.

Announcing a review of her party's position on the issue, she called for Holyrood to raise more of the money it spends in future.

Her comments have signalled a significant shift in Tory thinking over increased devolved powers.

Ms Davidson said she would outline detailed plans before the 2014 independence referendum.

During a speech in Edinburgh, the Tory leader said Conservative peer Lord Strathclyde, former leader of the House of Lords, would lead the review.

It will examine whether domestic powers currently reserved to Westminster are better off with the Scottish Parliament.

The SNP said Ms Davidson was lacking in credibility, adding that only independence would give Scotland the powers it needed to grow properly.

When Ms Davidson launched her successful campaign for the Scottish Conservative leadership in 2011, the Glasgow MSP described proposals on new Holyrood financial powers - which have since been agreed - as "a line in the sand", and strongly opposed calls for full fiscal autonomy.

Ms Davidson said it was now time for her party to turn over a new page, adding that with hindsight, Conservatives were wrong to oppose the idea of a Scottish Parliament during the campaign for devolution, which was delivered in 1999.

She said her party had been listening to the people of Scotland, adding: "We have heard their ambition for a devolved parliament - within the United Kingdom - with greater powers than it currently holds.

Ms Davidson notes in her speech that 'you learn from experience'. The experience driving her, I feel certain, is that of her party being routinely thumped in elections

"We have listened, we have heard and we will act. We will respond positively to that ambition.

"In doing so, we reaffirm our unshakable conviction that continued membership of the United Kingdom is the cornerstone of a safer, fairer and more prosperous Scotland."

Scotland's budget is currently funded by a Treasury grant and, although Holyrood already has some tax-varying powers, they have never been used.

The new Scotland Act, passed last year, transferred tax and borrowing powers from Westminster to Holyrood, including the ability to set a Scottish rate of income tax from 2016.

Ms Davidson said those spending the public's money must be accountable to the public both for how it is spent and raised.

She said: "So, the Scottish Conservatives are committed to a new path - more responsibility for the Scottish Parliament and a strengthening of devolution."

Ahead of the Scottish government's independence referendum on 18 September 2014, Ms Davidson said: "A vote next year for Scotland to stay within the United Kingdom will be a vote to strengthen devolution.

Strathclyde review The Conservative review will ask a series of questions on each of Westminster's domestic reserved powers before arriving at a view on whether they should be devolved. These include: Would its devolution reinforce or weaken the place of Scotland within the United Kingdom? Would it strengthen the accountability of the Scottish Parliament to the people of Scotland? Would it preserve the benefits Scotland gains from being part of UK-wide systems? Would it improve the quality of the government of Scotland? Would the decision-making be improved if taken as close as possible to the individual citizens directly affected?

A vote for the Scottish Conservatives at the next general election will be a vote to increase the power and responsibility of the Scottish Parliament and to take Scotland forward.

"The responsibility of each of us, of all political parties who share a belief in Scotland and in the United Kingdom, is to empower the Scottish Parliament in a way which meets the ambitions and aspirations of the Scottish people while strengthening the partnership of the four nations of our United Kingdom.

"It is a responsibility the Scottish Conservatives are committed to honouring in full, on behalf of the people of Scotland.

Former Scottish Tory leader Annabel Goldie and Conservative MSP Alex Fergusson, the previous presiding officer of the Scottish Parliament, are also playing a role in the Strathclyde review.

It will also seek independent advice from Alan Trench, from Edinburgh University's school of political science and Adam Tomkins, from the University of Glasgow law school.

SNP MSP Annabelle Ewing said the The Tories were "split from top to bottom" on the issue of more powers for Scotland.

"With this announcement, it is not the infamous 'line in the sand' that has disappeared - it is the last vestiges of Ruth Davidson's credibility," she said.

"The only reason Ruth Davidson and others in the anti-independence parties are grudgingly talking about more powers for the Scottish Parliament is because we are going to have an independence referendum next year to achieve these very powers - and more."