Swathes of Ireland’s broadband infrastructure will be better than Britain’s within a few years, after Vodafone signed up for a €450m (£358m) joint venture to string fibre-optic cables along power lines.

Alongside the Republic’s state-owned electricity board, ESB, it will create a broadband network providing download speeds of between 200 and 1,000 megabits per second to half a million homes and businesses in 50 Irish towns. That represents roughly a quarter of premises nationwide and there is scope in the plans for further expansion.

By comparison, BT’s superfast broadband network, which currently covers around two thirds of premises, provides typical top speeds of around 80 megabits per second.

Britain is currently above Ireland in international average speed rankings but is likely to fall behind once Vodafone and ESB build their new network.

It will be up to 12 and a half times faster because the pair will roll out fibre-optic cables all the way into premises. Almost all BT’s upgraded network relies on old copper wires for the final hop from a cabinet on the roadside into homes and businesses.