Runaway teacher Jeremy Forrest is due back in the UK after going on the run with his pupil, sources said.
The 30-year-old married amateur musician, from Ringmer, East Sussex, is understood to be at a French airport awaiting a flight.
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Witnesses reported hearing a "huge bang" at the venue during the concert on Monday evening.
ITV News travels to Britain's eastern-most city to gauge how the electorate will be casting its votes.
Carefully choreographed campaigns can become unstuck because voters have the power to peel back a politician's veneer.