Theresa May's plans to double the plastic bag tax to 10p is being opposed by the Treasury amid concerns that it looks like "profiteering", The Daily Telegraph can disclose.

The Prime Minister is this week expected to unveil proposals to hike the levy in order to accelerate the clampdown on one-use and disposable bags and encourage more consumers to take up recyclables.

The charge has been hailed by environmentalists for achieving an 85 per cent reduction in plastic bags since October 2015, when the scheme was first introduced in England.

However a senior Treasury source told The Daily Telegraph that the additional levy is unnecessary: "The 5p tax has already worked and dramatically reduced the use of plastic bags. If it's raised to 10p it looks like profiteering.