Concerns have been raised after Prime Minister Gordon Brown announced new plans to allow staff the right to request time off for work training.

And that has been followed by a series of recommendations that parents of children aged up to 16 years should also be allowed to request flexible working.

The growing burden of legislation and regulations has been a frequent cause of complaint from business which claims it is costing £6.9 billion a year in the east of England alone – although ministers say they are working to reduce red tape.

Now business organisations are urging the Government to delay implementing the new measures until firms are sure they can meet the new demands.

Operations director for the east of England manufacturers' association the EEF Steve Jackson said: "Business will find it difficult to understand why the Government is adopting such a bullish approach to Better Regulation, while at the same time introducing yet more regulatory requirements, which will inevitably create practical problems.

"Our evidence suggests while many companies had seen the benefits of flexible working, a majority had experienced problems in adapting to the new legislation.

"Giving yet more employees the right to request time off will impact especially hard on the smallest companies, which are already struggling to adapt to flexible working."

The CBI's east of England regional director Richard Tunnicliffe said: "The right to request flexible working has worked well, precisely because it is a 'right to request', not a 'right to have'. In nine out of 10 cases, employers and employees agree a practical arrangement that suits both.

"But extending the right to another four and a half million parents is a big step and the Government must give firms enough time to prepare, particularly small firms that lack the HR resource of big companies. The extension should come into effect no sooner than October 2009 – not next April."

An extra 4.5 million parents in Britain will gain the right to request flexible working, following the publication of an independent review today.

Business Secretary John Hutton said: "An extra 4.5 million parents who need more help balancing work and family life will get a big boost.

"It can also help employers, who often find they get the best out of mums and dads when they allow them to work flexibly."

He added: "It is important employers retain control over deciding whether it suits their business to allow people to work flexibly, but extending the right to request to parents of older children will allow families to take priority when decisions are made."