LONDON (Reuters) - The new Labour government will have to act fast to get Britain back on track to meet its 2030 climate target, with just a third of the required emission reductions covered by a credible plan, the country's climate advisers said on Thursday.

As part of efforts to reach net zero emissions by 2050, Britain has a target to cut emissions by 68% by 2030 compared with 1990 levels.

Progress towards meeting this goal is off track after the previous Conservative government rowed back on some environmental policies, the Climate Change Committee said in an annual progress report.

"The country's 2030 emissions reduction target is at risk. The new government has an opportunity to course-correct, but it will need to be done as a matter of urgency," said Piers Forster, the committee's interim chair.

The report outlined ten recommendations including removing some levies from electricity bills to encourage the electrification of other sectors such as heat and transport and restoring the 2030 phase-out of new fossil fuel car and van sales which was pushed out to 2035 by the former government.

It said annual offshore wind installations must at least treble, onshore wind installations double and solar installations increase five-fold by 2030.

The market share of new electric cars needs to rise to almost 100% compared with 16.5% today, while 10% of homes will need a heat pump by 2030 up from 1% today, the report said.

It welcomed the government's recent decision to lift the effective ban on new onshore wind projects but said more effort was needed outside of the electricity sector.

"We need to see that level of ambition applied to heat pumps, EVs (electric vehicles) and tree planting," James Richardson, acting chief executive said in a briefing with journalists.

Britain has halved its emissions since 1990, with most of this progress coming from phasing out coal in the electricity sector.

(Reporting By Susanna Twidale; Editing by Christina Fincher)

By Susanna Twidale