Royal Bank of Scotland's shares jumped today amid plans to sell off large chunks of its non-core business and axe up to 20,000 jobs.

But the bounce in the shares, by 3.1p to 22.4p, came as some analysts were busy slashing their recommendations on the stock. Société Générale put out a sell notice to clients, saying the shares were only worth 5p because of the high risk of the bank being nationalised outright.

RBS reports its 2008 results on Thursday. New chief executive Stephen Hester is meeting Treasury officials today to agree terms for the Government's insurance scheme for banks' toxic assets.

Today's share price rise added more than £1 billion to the value of the bank. But the shares have lost more than 90% of their value in the past year, languishing far below the 65.5p the Government paid to give the taxpayer a 68% stake.

Hester plans to split RBS into two. The core will be based on UK retail and commercial banking while the other part will include remote and non-vital operations such as aircraft leasing and Charter One in the US. Businesses in Asia and Australia will be part of a £300 million sell-off.

Despite that, SocGen analyst Asheefa Sarangi warned ahead of Thursday's announcement: “We believe that there is risk to the downside if the outlook is particularly weak as this will heighten concerns about the bank's ability to continue to operate as a private-sector player.”

Not all were so gloomy. Credit Suisse said if the Government's insurance scheme turns out to be as big as the £500 million reported this week, it should keep British banks out of public ownership.