The Socialist deputy has also said the UK Prime Minister had performed several “U-turns” in her most recent negotiations.
His comments come after the EU signalled on Friday that sufficient progress had been achieved in the three red line issues - the Irish border, citizens’ rights and the divorce bill - for the talks to progress to the next phase.
May was on Monday updating the UK House of Commons on the Brexit negotiations.
A summit of EU leaders and heads of state in Brussels on Thursday is expected to give the green light for the talks to move to other issues, such as trade, in the New Year.
But, speaking on Monday, Corbett was highly critical of the dramatic deal brokered at the end of last week between May and European Commission President Jean-Claude Juncker.
He told this website, “Two months after its first ‘final deadline’, nine months after Theresa May triggered Article 50 before she was ready, 18 months after the referendum, and following a week of serious embarrassment and frantic night-time meetings, the long awaited ‘sufficient progress’ in phase one of the Brexit negotiations seems to have been achieved after a number of U-turns by the government.
“And this was, in the words of Donald Tusk, the ‘easier part of the task’, before moving onto the far more important second phase.”
Corbett said, “Even this deal fudges many key issues, and raises new ones. It has given rise to conflicting interpretations within hours of it being published.
“Some see it as a victory for the hard-line Brexiteers but many hard-line Brexiteers see it as caving in. The Leave.EU campaign has called May a ‘traitor’ who has ‘betrayed leave voters’. Nigel Farage has tweeted ‘The British Prime Minister flying through the night to meet three unelected men and agree to every single one of their demands is humiliating for our country’.”
He added, “So, it is no surprise that the document is riddled with language that can give rise to contradictory interpretations, or that leaves key points unsettled.”
Corbett, who heads up the UK Labour delegation in Parliament, said that “many issues remain unclear or unsettled.”
He cited the organisation “The 3 Million” which lobbies on behalf of citizens from other EU countries living in the UK.
Corbett said, “It says the agreement is a flawed compromise, pointing out that many guarantees are time-limited and many people who have made the UK their home are still in the dark about whether they will qualify for settled status.”
Speaking on Sunday, the British Brexit Secretary David Davis said the UK is seeking a “Canada, plus, plus, plus [Brexit deal) but including services which the Canada-EU (CETA) deal doesn’t [include], with individual specific arrangements for aviation, for nuclear, for data.”
Asked whether that is achievable in the Article 50 time-frame, considering CETA took seven years, Davis replied, “It’s not that complicated…The first thing is we want an overarching free trade deal which has no tariffs.
“Secondly, we start in full alignment; we start in complete convergence with the EU and so we then work it out from there.”
Davis stressed that it was significant that the joint report on the withdrawal terms had replaced “no divergence” with “full alignment” as “no divergence would have meant actually taking cut and paste rules…[with full alignment] we’ll have similar outcomes” but “we’ll have different methods to achieve them.”
On the Irish border issue, Davis insisted that the government is committing itself to “maintaining a frictionless invisible border,” but said the deal struck with the EU is “much more a statement of intent than it was a legally enforceable thing.”
On the financial settlement Davis said the Treasury’s “estimate” is “something like £35bn, £39bn” but it’s conditional on getting an implementation period and conditional on a trade outcome.