The Government’s asylum reforms would “fail to meet the UK’s human rights obligations” and risk exacerbating an “already unacceptable” backlog of claims, a group of peers and MPs have warned.

The Joint Committee on Human Rights (JCHR) has been reviewing proposed laws contained in the Nationality and Borders Bill currently going through Parliament.

Its latest report scrutinising the provisions in the Bill warns that segregating “different categories of refugee” based on how they arrived in the UK “would be inconsistent with the Refugee Convention and potentially a discriminatory breach of human rights”.

Instead of combatting people smugglers, the legislation would “penalise asylum claimants” for not using safe and legal routes to the UK which “lack sufficient capacity to support them”.

This and other plans as part of the overhaul, such as introducing the possibility of offshore processing of asylum claims, “risk undermining the humanitarian and cooperative principles on which refugee protection is founded”, the committee said.

Changes to how the age of asylum seekers is determined may lead to more children being “wrongly identified as adults, with severe consequences which would amount to a denial of children’s rights” and there was “no justification” for plans to use scientific methods to determine age “given their inaccuracy”, the peers and MPs warned.

Another element of the Bill which would allow the Home Secretary to remove someone’s citizenship without notice, such as in the interests of national security, “undermines the principle of fairness” and should be scrapped, the group concluded.

Joanna Cherry, the committee’s deputy chairman, said: “The UK has a proud history of championing the human rights of refugees. We should continue in this tradition and do all we can to be a place of welcome and support for people who have been persecuted.

“The Bill is at odds with the Refugee Convention and with our human rights obligations and should be amended.

“Rather than coming up with new punitive measures and lambasting the difficulties in rejecting asylum applications, the Government should focus on dealing with the lengthy backlog of cases.

“Fundamentally this Bill increases the likelihood that the UK turns its back on people it should be helping. This would be wrong and the Government needs to rethink these proposals.”

A Government spokesperson said: “The Nationality and Borders Bill will stop the abuse of our system and give victims who have been exploited the support they need to rebuild their lives.

“It is compliant with our legal and international obligations. It will continue to offer protection to the most vulnerable and step up measures to break the deadly trade of people smuggling.

“The power to deprive British citizenship on ‘conducive to the public good’ grounds is used sparingly, complies with the UN Conventions on Statelessness and always comes with a right to appeal. The Bill does not change this.”