The traditional 'old boys' network' is still prevalent at the top of many UK companies, despite the raft of HR initiatives and regulations of the past 10 years.

More than a quarter of managers still feel excluded or unable to realise their career aspirations because of social pressure or senior workplace cliques.

A poll by the Chartered Management Institute and recruitment agency Adecco shows that 27 per cent of managers still feel restricted by old boys' networks, and that almost half of all managers are fed up with a lack of career progression.

The study of more than 1,800 managers identified flat management structures (48 per cent), exclusion from an inner circle (27 per cent) and a lack of training opportunities (23 per cent) as the biggest barriers to career progression.

Richard Macmillan, managing director of Adecco UK and Ireland, says employers must do more to recognise achievement and develop career paths or risk losing talented individuals.

“Talented people will move if they are no longer satisfied in their role, and organisations need to start listening,” he said.