Suella Braverman has taken a swipe at Rishi Sunak, claiming he lacks the "political will to take on the European Court of Human Rights".
She accused Strasbourg of overruling the "will of the people" by preventing flights to Rwanda from taking off.
Speaking at the National Conservatism Conference, the former home secretary said the current Government hasn't "laid the groundwork" to quit the ECHR - despite Sunak suggesting he is willing to do so.
She added: "It’s no surprise that recent noises in this direction are easily dismissed as inauthentic."
Suella Braverman has taken a swipe at Rishi Sunak, claiming he lacks the "political will to take on the European Court of Human Rights"
PA/GBN
The former Home Secretary warned the Government against including a plan to withdraw from the convention in an election manifesto.
She said: "It should be noted that any attempt to include a plan for ECHR withdrawal in a losing Conservative Party election manifesto risks setting the cause back a generation."
Earlier this year, Sunak vowed to quit the ECHR if Strasbourg continues to block attempts to get flights to Rwanda.
He said that controlling illegal migration is "more important" than membership of the ECHR, saying he would not let a "foreign court" interfere with a policy that is "fundamental to our sovereignty".
The conference descended into chaos earlier today after police in Brussels ordered it to be shut down, sparking outrage from speakers and guests alike.
With political heavyweights including Nigel Farage and former Home Secretary Suella Braverman in attendance, the National Conservatism Conference (NatCon) had aimed to bring together voices from across Europe to share their views on the continent's future political outlook.
However, once Farage was on stage to address the gathered crowd, Brussels' mayor ordered organisers to wrap up the conference within just 15 minutes.
The former Home Secretary warned the Government against including a plan to withdraw from the convention in an election manifesto
PA
A report in local outlet the Brussels Times had said "anti-fascist" protesters were threatening the venue with mass protests, and had demanded the event be called off entirely.
Police told GB News they had issued a public order notice due to the "threat of protest" at the event, though sources at the scene reported there had not yet been any sign of demonstrations.
Farage, as he extended his speech to start taking questions from the audience, said: "I've heard the police are very eager to close us down, so they can close it down with me on stage."
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The former Reform leader slammed the decision to close the conference as "monstrous" and slated what he called the "extreme intolerance" of authorities in interviews after his speech, asking: "What will this look like around the world?"
Braverman's remarks about the ECHR come as the House of Lords gears up to vote on the Government's Rwanda legislation this evening.
The bill, which seeks to address legal challenges to the deportation plan, has been ping-ponged between the Commons and the Lords.