Thatcher strike last must stay, Brown tells unions

Mr Brown, who will oversee crunch talks with the unions later this month, opened the door to a deal on flexible working instead.

He flatly rejected demands from union leaders for a return to the right to launch secondary industrial action to support other workers.

But he gave a signal that the Government is preparing to agree with the unions' calls for a further extension of the right to request family-friendly working hours.

They want workers with children up to the age of 16 to take time off if their child is sick or needs to be taken to a school event or exam.

Thatcher laws to stay: Brown will not countenance extreme union demands

There has been increasing concern over the influence of unions on Labour policy.

The unions now give £9 in every £10 donated to Labour HQ and are preparing a shopping list of demands before their talks with ministers the day after the Glasgow East by-election on July 24.

Mr Brown, speaking to journalists en route to the G8 summit of the world's richest countries in Japan, indicated that even if he is weakened by the loss of Glasgow East he would not countenance some of the more extreme demands of the unions.

These include the abolition of key planks of Margaret Thatcher's anti-strike laws and a call for National Insurance rises on anyone earning more than £40,000 per year.

The Prime Minister said: ' Successful governments are those whose eyes are fixed on the future, not harking back to the past.

'The global economy is undergoing a massive change.

'The countries that prosper in the future will be those that combine fairness with flexibility to achieve full employment.

'There will be no return to the 1970s, 1980s or even the 1990s when it comes to union rights, no retreat from continued modernisation, and there can be no question of any reintroduction of secondary picketing rights.'

But his hint at yet more flexible working will anger business groups which argue that they are still struggling to implement a tide of new rights introduced by the Government.

Labour has given millions the right to request flexible working hours, including parents with children up to the age of six and carers. The same rights will soon apply to parents of children up to the age of 16.