Samantha Cameron visited Syrian refugees in Lebanon in March and is cited as the "biggest explanation" for the Prime Minister's stance over the conflict.
Sources close to Mr Cameron confirmed to the paper that his wife had pushed for a more robust response to the humanitarian crisis.
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The Olympian was one of several sports stars who opened up to the prince during an event for his mental health charity Heads Together.
There will be sunny spells, with temperatures peaking at 23 Celsius (73F). However, Northern Ireland will experience frequent showers.
Scottish X-Men star Alan Cumming under fire for 'offensive' comments blaming Brexit vote on 'stupid English people'.