Mr Jovanovich survived a double lung transplant in March last year and returned to work full time in September. However, side effects from ongoing medication are thought to have made it impossible for him to continue running a business that accounts for 60 per cent of Pearson's group sales and 64 per cent of its operating profits. Based in the US, Mr Jovanovich was also unable to make international flights after the lung operation. Mr Jovanovich's departure is officially described as "long-term medical leave". The 55-year-old has been responsible for building up Pearson's most successful business and many in the City had seen him as an obvious candidate to succeed Dame Marjorie Scardino as group chief executive. The company intends to revert to the management structure put in place when Mr Jovanovich first went on medical leave early last year.Instead of seeking a replacement for him, the three most senior members of Pearson Education's management will report directly to Ms Scardino. In the last full financial year, Pearson Education contributed pounds 2.4bn to the group's pounds 4bn of sales, and pounds 313m of operating profit out of the group's pounds 490m.Mr Jovanovich said: "For over 30 years publishing has been my vocation and it was difficult to spend even a short time outside the industry.

I now need to step back from the responsibility of running a $4bn international company.". The news will be welcomed by shareholders and analysts in the City who have recently started to regain confidence in the telecoms group. THE GOVERNMENT could be handed a pre-election windfall from plans that emerged yesterday to rush out a report on value for money in public services just before polling day. The Office of National Statistics said it planned to incorporate major changes to the way the output of education, public order and social services are calculated when calculating economic growth.

Len Cook, the National Statistician, said he aimed to publish the changes to historic figures in nine key areas "before the end of April". The figures could potentially lead to a massive improvement to the measurement of public sector output and productivity going back several years for areas such schools, childcare, prisons and the police.The issue of value for money in public services will be a key election battleground in the wake of claims by the Conservatives that the billions of pounds the Government has poured in are being lost in wage rises and red tape. The changes follow the publication yesterday of a year-long review by Sir Tony Atkinson, a leading academic economist, that made more than 50 recommendations on the way the ONS produces its public sector growth figures.The issue was plunged into controversy after it emerged Mr Cook would have the power to decide whether to publish those figures if a general election is called for 5 May.The ONS confirmed it would follow government guidance, which says Mr Cook can decide whether to release ad hoc statistics during a hustings period. It risks a repeat of a political row a year ago when the ONS used Sir Tony's interim findings to produce figures showing that NHS output had risen 29 per cent between 1995 and 2003. This was up from the 19 per cent previously calculated, adding as much as 0.1 per cent to annual GDP.