Home Secretary Theresa May has agreed to a review on the proposed Investigatory Powers bill.

The review will be led by the government’s reviewer of anti-terrorism legislation, David Anderson.

Labour, which had previously abstained from voting on the second reading of the bill on 15 March, welcomed the review.

Labour had also pushed May to promise that the powers would not be used to spy on trade unions.

Shadow Home Secretary Andy Burnham tweeted: "Proud to have won a commitment from Theresa May that #IPBill will be amended to exclude "legitimate trade union activity". Historic change."

Burnham said that his party still wanted to see "significant movement" on the bill but welcomed the fact that the Home Secretary was "listening".

The bill will provide the UK Government with new far-reaching abilities to legally conduct surveillance on citizens, including tracking their activity online. The Government claims that the new powers will help it prevent terrorist attacks.

May intends to get the act into law by the end of 2016, in order to replace existing laws before they expire. This will be the first comprehensive legal framework for state surveillance in the world.

It has attracted significant criticism, including from the Intelligence and Security Committee, particularly over a lack of clarity in the definitions included in the text.

Hanna Thomas, Campaign Manager at SumOfUs, told CBR in an interview prior to the bill’s reading that the bill’s requirement for records to be collected and stored will "leave us wide open to leaks and hacks of our data".

Thomas called the bill a "cynical power-grab", and cited the bill giving local authorities power to use mass surveillance to fight benefit fraud as an example of how the bill is overstepping its reasonable boundaries.

Many commercial organisations such as Google and Apple have opposed the legislation, as has the Liberal Democrat party.