Boris Johnson and the Confederation of British Industry (CBI) have called for changes to the law to make it harder for workers to take strike action.

As London currently suffers from another 24-hour tube strike the Mayor wants the government to introduce legislation preventing action unless at least 50% of union members in a workplace take part in a ballot.

As the law currently stands industrial action can take place even if only 1% of those polled respond - as long as there is a majority in favour. There are concerns that the country's productivity will be negatively affected over the coming months as union leaders urge mass action against the government's planned spending cuts.

The CBI have called for the notice period for industrial action to increase from seven to 14 days after the ballot takes place to give businesses more time to prepare for strikes.

"The law needs updating to reflect the fact that 85% of private sector employees are not members of a union, and that most employers now negotiate directly with staff or their representatives to bring about changes in the workplace," said CBI deputy director-general John Cridland.

"While workers have the legal right to withdraw their labour, employers have a responsibility to run their businesses. The public increasingly expects it to be business as usual, even during a strike, so firms must be allowed to hire temps directly from an agency to provide emergency cover for striking workers."