LONDON (REUTERS) - British lawmakers are debating a bill that aims to deliver on the Brexiteers' promise of independence from Brussels.

"So much for taking back control," Shadow Brexit Secretary, Keir Starmer said.

However, Labour's Brexit spokesman is among those to say it might just hand too much power to ministers instead.

The EU withdrawal bill aims to end the supremacy of EU law - converting it into UK legislation.

Opposition parties call it a power grab by government that overrides parliamentary oversight, and some Conservatives agree.

"If the government isn't going to move in the next two days of debate, well I think we may have to force it to go back to the drawing board and try again," Conservative MP, Ken Clarke said

On Thursday, the government represented by Brexit Secretary David Davis, gave the defence in rowdy exchanges.

"This does not aim to change law this aims to maintain, it is primarily technical in that respect and aims to maintain the laws we currently have," Davis said.

The first vote will take place Monday and it would only take a few rebels to defeat the government.

Prime Minister Theresa May is short of a majority since June's election, and is dependent on support from some Northern Ireland lawmakers.

Next up, the unelected House of Lords will have their say.

Meanwhile the real debate - between the UK and the EU - is gathering pace.

The back and forth between negotiators David Davis and Michel Barnier so far producing few solutions, but plenty of barbs.

On Thursday, Barnier shot down Britain's position on Northern Ireland

"The UK wants to use Ireland as a kind of test case for the future EU, UK customs relations. This will not happen," Barnier said.