The Guardian has developed plans to erect a paywall around its website and apps if its existing membership scheme and appeals for donations do not meet financial targets amid upheaval in the news market.

It is understood that the publisher has called in consultants to work on the details of compulsory subscription charges for some material, despite the growth of voluntary contributions. The proposals are "finished and ready to go", a source said.

The Guardian is resisting the introduction of a paywall, however. It wants to maintain free access to its journalism online to preserve its reach and influence. Nevertheless plans have been developed as a contingency that could be triggered if its turnaround effort fails to end years of heavy losses on schedule.

A source said there were no current plans to erect a paywall but added: “We will keep all options under consideration in order to achieve break-even.”

The publisher said Tuesday that its current strategy was on track and that by April it had attracted 230,000 paying members online, up from 50,000 at the start of the financial year.