And with that, Mr Faull's appearance in front of MEPs has finished.
- MEPs on the Constitutional Affairs Committee took evidence from Jonathan Faull, the British official who led the EU Commission's UK negotiation taskforce.
- It follows an EU summit last week, at which David Cameron finalised the terms of a deal to change the terms of the UK's membership, ahead of an in-out referendum in June.
- The Commission has said the taskforce will remain in place for the time being to deal with technical questions arising from the proposed changes.
- Certain aspects of the deal - including changes to child and in-work benefit payments to EU citizens - will require eventual approval of the European Parliament.
Responding to the questions about the legal status of the deal, Mr Faull confirms that the agreement is "not a new EU treaty", but can be considered legally binding in international law.
He adds that securing the final agreement was "hard going" to secure.
In response to Mr Helmer, he says that the document is the "clearly expressed will" of all governments - and the Commission expects EU states to enforce it.
He adds that the document "is a done deal".
In response, Jonathan Faull says that the commitment to 'ever closer union' has "never been a legal basis for legislation".
He also says that the commitment has always had to sit alongside the "reality" of EU politics.
On the other parts of the deal, he confirms that nothing in the deal requires immediate treaty change to come into force - and that nothing in it is incompatible with the current treaties.
Responding to Mr Leinen's question about disputes over future interpretation, he says he is confident the language is "pretty clear".
However, he adds that he "can't rule out" future semantic disputes in the future, since this is just "human nature".Copyright: BBC
German social democrat Jo Leinen asks Jonathan Faull whether the finalised deal is in danger of creating a "permanent conflict" of interpretation.
In particular, he questions whether the UK's "general opt-out" from further co-operation might have "consequences that we don't foresee".
UKIP MEP Roger Helmer asks Jonathan Faull to confirm that the final agreement is "not a done deal" but rather the "promise of future delivery".
He also adds that elements of the deal could be subject to challenge in the European Court of Justice.Copyright: BBC
Apologies - for the moment, our webstream of the committee is currently not working.
We will try to rectify this as soon as possible.
You can, however, watch the sitting here for the time being.
MEPs will have to give their approval to any EU legislation that is required to put the terms of the deal into reality.
The changes in the final deal relating to limiting child benefits, tightening up the rules on “sham marriages” and the emergency brake on in-work benefits would all require their approval.
They will have to vote on a legislative proposal made by the European Commission, although this wouldn’t be drawn up until after the UK had voted to remain in.
This would be done under the “ordinary legislative procedure” – which essentially means they would need approval from at least 376 of the 751 MEPs.
Downing Street has said the leaders of the Parliament’s three biggest groups have "made clear their support" for the deal.
However, Parliament President Martin Schulz has said the exact nature of the legislation – including possible amendments – cannot be “pre-empted”.
Notably, Gianni Pitella, the Italian social democrat who leads the second-largest group, has previously said he is “very concerned” about changes relating to workers’ rights.
You can read more about the different political groups in the European Parliament here.Copyright: European Parliament
The Kent-born official has been a civil servant at the European Commission for over 30 years.
He has previously been the senior civil servant at the Commission’s financial services department, where he was responsible for overseeing work on EU financial services legislation.
He has also worked in the Commission’s competition department and worked as one of the Commission’s senior press officers.
He has previously expressed scepticism about whether the UK could continue as a non-EU member of the single market, without having to abide by EU regulations.
In an article for the European Parliament’s in-house magazine in 2013, he said that “the reality of modern Europe is that economic rules of this sort are made in Brussels”.
"The only question is whether Britain will be at the table shaping them or just receiving them by email after some form of consultation," he added.
Hello and welcome to coverage of this meeting of the European Parliament’s Constitutional Affairs Committee, which is due to get underway shortly.
This morning, MEPs are due to be taking evidence from Jonathan Faull, the British official who leads the Commission’s UK negotiation taskforce.
The small unit of officials was set up last summer to co-ordinate negotiations between the UK government and the European Commission.
Voters in the UK are due to vote on whether to remain in the EU during a referendum on June 23.
It follows a summit of EU leaders last week, at which David Cameron finalised a deal to change the terms of the UK’s membership.