ITV said the programme was the highest rating show of the year so far, nudging ahead of a Coronation Street which pulled in 11.2 million in January.
Adding viewers for ITV's +1 channel brought the audience to 11.9 million for the BGT finale, with a peak audience of 14.5 million.
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Sunday evening's weather for the east of the region
Sunday evening's weather for the west of the region
Fifteen of the remaining little ships that helped evacuate the beaches of Dunkirk in WWII have gathered in Chatham