Tory Solicitor General Robert Buckland dismissed a string of amendments from backbenchers seeking to retain existing Brussels regulations as “unnecessary”.
And he vowed that leaving the EU would “in no way whatsoever” be used as a pretext to cut protections for workers’ rights.
He spoke out after former Tory Cabinet minister Dominic Grieve demanded extra safeguards on the second day of detailed Commons discussions of the Government’s EU Withdrawal Bill.
MPs are due more than 60 hours over the next few week scrutinising the measure, which seeks to lay the legal basis for a smooth departure from the EU and transfer existing Brussels law to the UK statute book.
Mr Grieve, a former solicitor general, feared regulations imported from Brussels could be “brought to the lowest possible status on their return here”.
Labour’s Shadow Brexit minister Matthew Pennycook, said ministers could “chip away at rights, entitlements, protections and standards that the public enjoy and wish to retain”.
Mr Grieve said: “He’s right about that – that is the curiosity of this legislation, that taking laws which we would regard for the most part in this country of being of very considerable importance if you were to speak to them, to raise the issues with the public, are being brought to the lowest possible status on their return here and without there really being an opportunity for obvious reasons for us to revisit this issue domestically in a way which might lead us to enacting fresh legislation.”
Labour’s new clause 58 seeks to ensure retained EU law has a level of enhanced protection.
Mr Grieve wanted an assurance from Government that the matter was being looked at.
He added: “I don’t wish to force the Government’s hand, even though that might appear superficially attractive.
“I don’t actually wish to put this amendment to the vote.
“It has problems of its own.
“But I put the Government on notice that we are going to have to draw together the issues that we’re debating today, and indeed I’m convinced it will be similar issues next week, all of which derive from the same problem, as to the way the Government has approached this and drafted this legislation at the moment, and it must be remedied.”
Mr Grieve said he was happy to work with the Government and reform the legislation to build a consensus across the House.
During Prime Minister’s Questions earlier on Wednesday, Theresa May said the Government was listening to the contributions being made in the debate and “listening carefully to those who wish to improve the Bill”.
She added: “I hope that we can all come together to deliver on the decision that the country took that we should leave the European Union.”
Seeking to dismiss concerns, Mr Buckland said: “The Brexit process will in no way whatsoever be used to undermine or curtail the rights of workers that have been enshrined both in domestic law and in law by virtue of the EU.”
He added there was an essential clause to preserve the domestic statute book and to provide certainty over what was domestic law.
He said: “I hope that today I can in my remarks and indeed by demonstration reassure members that the Government’s policy here is very clear, it is delineated and this is not some out of control grab of power to use this Bill which is a framework Bill, it’s very much a process Bill, to somehow then use this as the basis to change policy, that is not the intention of this Bill.”