The worker, 38, from Bridgnorth, who does not want to be named, escaped with minor burns to his arms and eyebrows and had his clothing singed following the 415-volt impact.

An HSE investigation into the incident that took place on 16 August 2011 found Ricky James, 46, the subcontractor responsible for the work, had incorrectly marked where the live cable lay.

Birmingham Magistrates’ Court heard that subcontractor James was responsible for scanning the pavement with a specialist tool to identify cable locations before work started.

After wrongly marking where the cable lay, he instructed the operatives to carry out the edging work. When the worker wrapped a piece of nylon around the steel pin it made contact with the 415 volt underground live cable and an explosion ‘like a roman candle’ occurred.

James pleaded guilty to breaching HSE regulations and was fined £2,500 and ordered to pay costs of £4,727.

HSE inspector Paul Thompson said: “The worker is very lucky to be alive. As he struck the pin it caused a ‘Roman Candle’ effect of fire and sparks to erupt from the ground, sending a jet of fire up from the pin.

“It is of vital importance that any buried services present on a construction site are located with diagrams. Their location must be marked and their presence made known to any operative who may work nearby.

“There are a number of ways of conducting similar work which avoids using steel pins to penetrate the ground.”