British Gas engineers are out on the first of five strikes to protest against the closure of the companies final salary pension scheme to new entrants.
Further 24 hours strikes are planned for 19 and 21 December, and 6 and 9 January, although the engineers have agreed to provide emergency coverage to vulnerable customers - they are front-line engineers who mend people's boilers.
6,000 workers are taking part, all of whom are GMB members.
