Negotiators at the Iran nuclear talks inched towards a breakthrough deal on Thursday but will need at least another full day if agreement is to be reached.
Baroness Ashton, lead negotiator for the EU countries, has been locked in talks with the Iranian delegation led by Foreign Minister Mohamed Javad Zarif.
If they succeed it will ease tensions, and fears of war, and give all sides six months to come to a more comprehensive agreement.
Sky News understands that each side has the draft text of what could be a final agreement in front of them.
Some sentences are in brackets, and some words underlined in red. These indicate the wording of issues which are contentious to one side or the other.
It is taking time to work through each one, and some have to be left so they can move on to others.
Scientific and language experts are also in the room ensuring that each side agrees they understand what the other means when using specific terms.
The Iranians want recognition of their "right" to enrich uranium for peaceful purposes and an easing of sanctions.
In return they would be expected to agree not to enrich uranium to more than 3.5% and possibly reduce their stockpiles already enriched to 20%.
There is also the issue of Iran's plutonium reactor which could come on stream next year.
There is another complicating factor meaning the talks can be expected to go on possibly past Friday: Baroness Ashton may be leading the negotiations but it is doubtful the Americans will give her the authority to sign off on a final deal without them seeing the full text and probably having their own face to face talks with the Iranians.
There are indications that the US Secretary of State John Kerry is preparing to fly to Geneva.
If that happens then the foreign ministers from France, the UK, Germany, and possibly Russia, may also fly in.
This is what happened 11 days ago when an agreement looked within reach. However, all sides left empty handed.
It could happen again as there are still several brackets and words underlined in red left in the draft text of the agreement.
There is a feeling here that they are closer than 11 days ago, but that the fundamental sticking points remain to be resolved.
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