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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The Electrical Safety First charity is warning homeowners to avoid using any electrical appliances that have been recalled.
Tuesday afternoon's weather for the east of the region
Tuesday afternoon's weather for the west of the region