The Conservatives have been accused of attempting to water down the Human Rights Act after announcing vague plans to "update" the legislation in their election manifesto.
The 59-page blueprint, launched by Boris Johnson on Sunday, contains a promise to "update the Human Rights Act and administrative law to ensure that there is a proper balance between the rights of individuals, our vital national security and effective government".
The pledge comes after the the prime minister vowed to end prosecutions of ex-soldiers accused of murder during the Troubles in Northern Ireland, which would involve amending the act to exclude deaths before the legislation came into force in October 2000.
Tory MPs and members of Northern Ireland's Democratic Unionist Party (DUP) have long called for an end to prosecutions of veterans over killings during the Troubles, in an attempt to protect the armed forces from vexatious prosecutions.
But such a change to domestic legislation could put the UK at odds with the European Convention on Human Rights, according to legal experts.
Christine Jardine, Liberal Democrat home affairs spokesperson, said: “We’ve known for years that the Conservatives want to undermine the Human Rights Act that safeguards our individual freedoms, and their manifesto confirms it.
“When the Tories say they will ‘update’ the Act, there’s no doubt that they mean weaken it.
“They tried during the coalition, but the Liberal Democrats stopped them. We will stop them again if they try now."
Plans to overhaul the Human Rights Act were unveiled as the prime minister laid out his blueprint to reunite the country after years of Brexit division.
Speaking in the West Midlands, Mr Johnson vowed to take the UK out of the EU by the end of January and "forge a new Britain" as he sought to turn his focus to domestic issues.
However a key pledge to deliver 50,000 new nurses fell apart within minutes, as it turned out to include the retention of 18,500 existing nurses.
The recruitment promise sat at the heart of a manifesto which also promised to invest £100 billion in infrastructure and introduce a Triple Tax Lock ruling out increases in the rates of income tax, VAT or national insurance until 2024.