European leaders have abandoned plans for bondholders to bear the brunt of sovereign debt collapses, following talks overnight to tackle the eurozone crisis.
The FTSE 100 has dipped back below 5,700 but remains on course to post its largest monthly gain since 1990.
George Osborne has said efforts in Europe to tackle the economic crisis are currently falling short of what is needed, warning the billions pledged by governments so far are not enough.
The FTSE 100 made up some of the ground lost in recent days, gaining over 100 points in early trading, amid talk in Europe of plans to recapitalise the banking system.
News that Greece will fail to meet deficit reduction targets pushed the FTSE 100 down 2.8% at open, dragging it below 5,000 points.
The FTSE 100 sold off sharply in early trading alongside indices across Europe as fears over a break-up of the region swept across markets once again.
Aviva Investors manager Justin Onuekwusi has taken over two funds following the departure of Jason Josefs, and is now running a total of five portfolios for the group.
Markets have continued to move higher following a co-ordinated effort by the world's central banks to inject liquidity into the banking system.
European equity markets are enduring another volatile session as rumours of funding shortfalls and eurozone intervention affect sentiment.
Markets on Wall Street opened higher for the fourth consecutive session as speculation the Federal Reserve is to take more action to stimulate the US economy continued to buoy investors.