Nemo Link, a joint venture between the UK's National Grid and Belgium's Elia System Operator, said it had started laying 59 km (37 miles) of a subsea cable in Kent, on the British east coast, while work at the Belgian end would commence next year.

Nemo Link is one of several plans to build interconnectors with France, Norway, Denmark and Belgium and its progress should allay industry fears that Britain's exit from the European Union will dampen such initiatives.

The National Grid, owner and operator of much of Britain's gas and electricity distribution network, voiced concern in January that Brexit could dampen investment as the UK loses its say over EU regulations of networks and power trading.

Average UK daytime demand for electricity is about 32 gigawatts, depending on the season, with generation primarily from gas-fired power stations, wind turbines and nuclear plants. Interconnectors to Europe increase Britain's flexibility to supply consumers with power.

"A well-integrated electricity grid is for the benefit of the consumers and the general welfare, as it provides access to cheap, renewable energy anywhere in Europe and allows to export excess energy when necessary," Elia Chief Executive Chris Peeters said in a statement.

Britain plans to build three new cables to France, adding 3.4 GW of capacity to the existing 2 GW, as well as its first interconnector to Norway with 1.4 GW of capacity and to Denmark with 1 GW of capacity, according to UK energy regulator Ofgem.

(Reporting by Sabina Zawadzki; Editing by Dale Hudson)