Millions more parents will be able to work part-time under an extension of the right to request flexible employment promised by Gordon Brown yesterday.

Imelda Walsh, a senior executive at Sainsbury’s, will lead a review into how many parents should be given the right to request that they do their jobs part-time, work from home or work flexitime.

The right to request flexible work is at present restricted to parents with children under the age of 6 and those who care for elderly or disabled relatives. Ministers say that they are genuinely open-minded about where to draw the line, but they have voiced sympathy with parents who want to be able to spend time with their children when they move from primary to secondary school at the age of 11 and during their key exams. That suggests an extension to parents with children aged 16 or even 18.

Ms Walsh has been asked to finish her review by the spring. An extension of the employment right will not require a new Bill, and can be passed using simpler secondary legislation.

Labour is under political pressure from the Conservatives to act swiftly.

David Cameron, the Tory leader, announced this year that all parents with children under 18 would have the right to request flexible work under a government led by him.

Some Labour ministers want Mr Brown to go even farther. Beverley Hughes, the Children’s Minister, has called for all employees to be given the right to request flexible work.

However, government officials said yesterday that they wanted to move forward with the support of business and if companies felt that a more incremental approach was better they would have the opportunity to have their views heard. Business leaders were quick to warn the Government that they would struggle with a sudden deluge of requests.

The Confederation of British Industry said that it would welcome a step-by-step approach. “The CBI welcomes the Government's plan to review when and how the right to request flexible working will be extended to parents of older children,” said John Cridland, its deputy director-general.

“It should beware of increasing numbers eligible to request too far too fast, however, as this could jeopardise the future flexibility of those currently eligible.”

The Federation of Small Businesses said that companies had to retain the right to organise their workforce to stay competitive. “The Government needs to recognise that the reality in a business is that the employees need to be at work to enable the firm to make money, pay their wages and grow to employ others,” said John Wright, national chairman of the FSB.

“The employer must continue to have the final say in granting flexible working to ensure that the business does not suffer. This way employees can benefit where appropriate from flexible working but the needs of the business will always be met.”

The Government introduced the “right to request” flexible work in 2003 for parents with children under 6. Since then, 22 per cent of eligible employees have requested it and about 90 per cent of requests have been granted. Well over one million more parents are now working flexitime, part-time or from home as a result.

About half of new mothers now work flexible hours, compared with fewer than one in five in 2002, and the proportion of new mothers who have changed their employer when returning to work has halved to 20 per cent in the same period.

Although the employer can refuse, he must show that the request has been considered seriously and, if it goes to tribunal, prove that he had a good reason to turn it down.

However, extending the right to all parents would be a big step, leading to the eligibilty of 7.3 million families.

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