Nationalist MEP Simon Busuttil has told the European Parliament's Civil Liberties Committee that the procedure used to draw up new guidelines for anti-immigration patrols are illegal and should not be approved.
Dr Busuttil, who is also his group's coordinator for the committee, decided to adopt such a stand following advice given by the EP's legal services section.
Speaking to The Sunday Times after the meeting, Dr Busuttil insisted the rules, which are not in Malta's interest, should be blocked.
"These new rules do not make sense and I have no intention of supporting them. In fact, I will do my best to have them rejected in the European Parliament," he said.
The guidelines, recently approved by the EU Council despite the objections of Malta and Italy, need the EP's consent to enter into force.
Intended to act as a new code of engagement for Frontex's patrol missions, the regulations will place responsibility for rescued immigrants and asylum seekers on the country hosting the mission.
For the past two years Malta has hosted the Frontex mission but has always maintained that immigrants found on the high seas should be disembarked at the closest safe port, in line with international conventions which Malta is party to. But on several occasions the rules of engagement sparked a rift between Malta and Italy.
Frontex wants the new rules to come into force before the next anti-migration patrol mission off Malta, scheduled to start in April. However, the new position adopted by Dr Busuttil may derail the process.
"According to EU procedure, the Frontex rules need the EP Committee's consent and if this is not given the guidelines will have to be scrapped," a spokesman for the EP said.
"The bold stance being taken by Dr Busuttil indicates that the European People's Party will try to block the rules. It now depends on the position taken by the other MEPs in the committee, particularly the Socialists and the Liberals," he explained.
Dr Busuttil said he would do his utmost to convince others that the proposed rules should be rejected, though he admitted it would be a difficult task.
"It will not be easy to muster a majority in parliament to reject them since the rules were already overwhelmingly adopted by the Council," he said.
Following the Council's approval of the new rules, Justice Minister Carm Mifsud Bonnici had gone on record saying Malta would not participate in Frontex missions if the new rules were enforced.
The final decision by the Civil Liberties Committee is expected to be taken in two weeks' time.