Failure to incorporate the EU charter of fundamental rights into UK law after Brexit sends out "a really strange message" about the attitude of the Conservative Party, a senior Tory has said.
Former attorney general Dominic Grieve said people now viewed things like LGBT rights "as being rights of a fundamental character".
He also accused ministers of a "paltry" response to the matter, adding that he hoped peers would revisit the issue when the European Union (Withdrawal) Bill makes its way through the Lords.
Ministers have previously said the rights in the charter will be protected and are maintained through other means.
Speaking at the Bill's report stage in the Commons, Mr Grieve said: "I listen very carefully to what the Prime Minister says about modernising the Conservative Party, about giving it a broad appeal to younger people, about trying to ensure that we reflect current norms and standards in our country and give effect to them in the sorts of policies we develop.
"And yet ... it does seem to me that in simply batting this issue away and saying don't worry, it's all going to be perfectly alright, without even coming up with a plan for the future about possibly adding a bill of rights clause or rights clauses to the Human Rights Act, we're sending out a really very strange message about our attitude on this side of the House to matters which I believe many people in this country now see as being rights of a fundamental character, particularly on issues like LGBT and things of that sort."
Mr Grieve, who led a Tory rebellion over the Bill at committee stage, said the Government had provided a mechanism where the rights in the charter could be invoked for three months after exit day, but not in a way which challenges primary legislation.
"I have to say that I think that the response on this matter is, frankly, rather paltry," he said.
"It is a minuscule change, although I will also say this, that minuscule though it may be, it is actually a little wedge in the door, because it represents quite a major surrender or change of principle on the part of the Government towards this issue."
Mr Grieve added that he did not think the Bill would pass through the House of Lords "without this issue being considered".
He said: "I very much hope that when this Bill goes to the Lords they will look at the amendment that the Government has tabled, understand its spirit ... but perhaps decide that it might be capable of a little bit of development."
Mr Grieve added there was an "internal incoherence" which was inevitable about the way in which retained EU law was being handled in the Bill.
He added: "We have here a problem which ought in fact to unite both sides of the House as to how we best go about retaining what is best of EU law.
"Though we have made some steps in the right direction, I have to say that I regret that I don't think we have yet got anywhere near enough to the point where I can feel really comfortable that we've done this as well as we should."