The leaders of two of Spain's largest energy firms said on Thursday the country should step up its biogas production goals if it was to accelerate a drive towards decarbonisation.

In June the government unveiled a draft update of its climate and energy plan that included a doubling of Spain's 2030 biogas production target to 20 terawatt hours (TWh).

Francisco Reynes, Executive Chairman and CEO of power utility Naturgy, said the plan needed to be "more ambitious ...when it comes to the role of renewable gases."

Spain was behind other European countries in that sector, he told an event hosted by newspaper El Economista.

Repsol CEO Josu Jon Imaz agreed that biogas targets should be raised, and called for energy policies based on technological neutrality - meaning setting no preference for which technologies should be used to reach greenhouse gas emissions reduction goals.

Renewable gas could help cut emissions in the short term, he said.

The June draft also set a national target of 11 gigawatts (GW) of electrolyser capacity to produce green hydrogen, up from a previous 4 GW goal.

On Tuesday, industry association Sedigas also criticiced the plan's "lack of ambition" on biogas, saying that Spain should aim to produce at least 35 TWh of biogas by the end of the decade. (Reporting by Pietro Lombardi; Editing by David Latona)