Scottish leader Nicola Sturgeon will accuse Prime Minister David Cameron of playing 'fast and loose' with Britain's place in the European Union on Saturday, criticising his renegotiation strategy before a public vote on remaining an EU member.
Britain's future in Europe has become a defining issue for the country. Cameron has promised to negotiate new membership terms before holding a referendum by the end of 2017 on whether to leave the EU.
A vote to leave would have profound consequences - among other things, it might trigger a fresh bid for Scottish independence by the pro-EU Scottish National Party, threatening to end the 300-year-old union of Scotland and England.
Sturgeon, who supports the European Union but eventually wants Scotland to become an independent country, will use a speech at her Scottish National Party's annual conference in Aberdeen to criticise Cameron's handling of the issue.
"We despair at the failure of leadership of a prime minister pandering to Eurosceptics in his party, but unable to articulate clearly and precisely what it is he is seeking to renegotiate," Sturgeon will say, according to advance extracts of her speech.