(Daily Mail) -- Michel Barnier and his negotiating team want Britain to be shackled to EU tax policies after Brexit, a leaked document suggests.
The EU's Brexit Task Force met with the European Parliament's TAX3 secretariat last week to discuss how Britain will align its tax rules with the EU.
Campaign groups fear this proposal will be used to deliberately undermine a post-Brexit economy.
The draft documents, written by the TAX3 committee, state: 'The intention is that they commit to continue to alignment with EU standards, including for their overseas countries and territories'.
'The mandate for the negotiating team is to define and create a level playing field, taking into consideration four main areas, of which one is taxation'.
Campaign group Leave.EU hit out at the proposals, and said: 'We voted Leave to take back control of our country, but now the corrupt EU wants to control our tax rates after Brexit.
'Spineless May will inevitably cave in & sell us down the river again.
'Sack her and get someone who will say NO!'
The report hinted at the UK still applying the EU's Code of Conduct on Business Taxation, which means the British government, and any future British government, would not be able to slash or amend its own tax rates.
By cutting taxes, some Conservatives argue Britain could become more competitive, with increased investment in the economy.
But the European Union could potentially stop any UK government doing this under the proposals, meaning the UK would not be able to have a competitive advantage over the EU.
The documents also state: 'The objective is that the UK will abide by the tools adopted at EU level to fight tax evasion/avoidance, namely Code of Conduct on Business Taxation, Exchange of Information Directives (DAC) including Country by Country Reporting between tax authorities, Anti-Tax Avoidance Directive (ATAD).'
The draft document also referred to how Britain 'will abide by tools adopted at EU level' to also fight tax avoidance, The Telegraph reported.
Campaign group Leave Means Leave also hit out at the plans, writing: 'These leaked documents confirm what leavers have feared all along, that the EU will stop at nothing to stifle Britain's competitiveness post Brexit'.
The paperwork was created after Michel Barnier's negotiating team met with the European Parliament's TAX3 special committee on taxation last Thursday.