U.K. justice ministers pledged to change the country's human rights laws, after radical cleric Abu Qatada was finally extradited to Jordan, following an eight-year deportation saga.
Qatada left the U.K. for the Jordanian capital of Amman early on Monday, where he will face charges for terror offences, which he denies. In 2012, the European Court of Human Rights (ECHR) blocked attempts to deport Qatada, saying there was a "real risk that evidence obtained by torture will be used against him".
Home Secretary Theresa May told Parliament on Monday that she wanted to "remove the many layers of appeals" available to foreign nationals at risk of deportation, with potential repercussions for cases like Qatada's. May also indicated the U.K. might leave the European Convention on Human Rights, saying that "nothing is off the table".
However, such a move would have serious political and legal impacts for the U.K. and the European Union (EU). "I think it would be incredibly damaging to the U.K., which presents itself as a leader on human rights around the world," Ben Ward, the deputy director of the Europe division of Human Rights Watch, told CNBC.
"If Britain were to withdraw, it would send a terrible message to other countries in Europe who have worse human rights records, and make their governments think about taking a similar avenue."
Ward added that the ECHR as an "important safeguard" for when national courts made wrong decisions.
A U.K. withdrawal from the Convention could also be negative for the ECHR itself, and the EU's position as a protector of human rights.
"The European Court's international standing would be damaged in having one of the key member countries in the Council of Europe withdraw from the court and the convention," said Roger Sahota, a member of the Law Society's human rights committee.
Details about opting out of the human rights treaty are buried deep within the Convention, which states that a country has the option of "denouncing" it, i.e. pulling out completely. However, a member-state that left would still need to comply with existing judgments, and the denunciation would not affect ongoing cases.
Leaving the Convention could throw the U.K.'s membership of the 47-member Council into question, as membership is dependent on signing up to human rights laws.
"Britain will probably have to leave the Council of Europe and it is unclear whether it would affect EU membership and other international treaty obligations," said Sahota. He warned that a "watered-down version" of the Convention could leave U.K. citizens in a weaker position if their human rights were breached by the state.
The debate about the U.K.'s relationship with Europe has intensified in recent months, with U.K. members of parliament backing a referendum on EU membership, to be held by 2017.
(View More: Should the UK Leave the EU?)
However, the Council of Europe appears to be responding to the U.K.'s concerns. It has introduced an amendment to the Convention that states that member-states enjoy a "margin of appreciation" in interpreting its guidelines. In addition, member-states have the "primary responsibility" to ensure citizens have the rights guaranteed under the Convention, while the ECHR has a subsidiary role. The amendment also reduces the time span in which applicants can appeal deportation from six to four months, in an attempt to avoid a repeat of the drawn-out Qatada case.