Prince William jokingly told employees at BAE Systems in Barrow-in-Furness, Cumbria that they can "get back to work" after watching him unveil a plaque at the factory.
The occasion was to mark the opening of a new suite of offices where the next generation of Britain's nuclear submarines will be designed.
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Labour strongholds tended to remain so - apart from a major loss for the party in Dudley.
Labour suffered a "terrible" defeat in Rhondda but has already won 16 Welsh Assembly seats as it looks to record a fifth term in office.
UKIP have made further gains in the local elections in the Anglia region and the Conservatives have won back control in Peterborough.