UK's far-reaching surveillance plans need significant work-lawmakers

LONDON, Feb 11 (Reuters) - The British government has significant work to do to justify allowing the authorities to spy on the public's internet use, one of the main planks of a new planned surveillance law, lawmakers said on Thursday.

Ministers must also spell out their plans on encryption to ensure that they will not force tech firms to provide a "back door" for spies, the parliamentary committee set up to scrutinise the proposed legislation said.

"There is much to be commended in the draft Bill, but the Home Office has a significant amount of further work to do before Parliament can be confident that the provisions have been fully thought through," Paul Murphy, the committee chairman said.

Last November, the government unveiled its plans for sweeping new surveillance powers, a watered-down version of a so-called "snoopers' charter" which was dropped in the face of huge hostility including from a similar scrutinising committee.

Britain says the planned bill was vital because police and the security agencies have fallen behind terrorists and serious criminals they are trying to track because of technological advances.

The British bill, which comes before parliament later this year, is being watched closely by governments and tech companies around the world due to its proposals.

(Reporting by Michael Holden; editing by Kate Holton)