Iran will begin to freeze part of its nuclear programme in return for the sanctions relief from January 20.
The deal, agreed between Iran and world powers after months of negotiation led by the EU's foreign policy chief Catherine Ashton, is hinged on Iran curbing its enrichment of uranium.
Officials have another six months from January 20 to agree a final settlement about the activity the West suspects is aimed at obtaining nuclear weapons capability.
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The government is encouraging motorists to think twice about buying diesel cars in a bid to improve air quality.
Atlantic frontal systems spread rain in from the northwest on both weekend days. Windy - with gales across the north and west but mild.
The band announced at a free concert on Friday that they would take over the event's Pyramid stage on Saturday June 25.