The maximum fine for breaking election laws should be increased from £20,000 to £500,000, a House of Lords committee has said. The reform is one of a number of changed to electoral laws which they say should be introduced "without delay".

In a sign of the broad support for such moves, to date more than 156,000 people have backed an openDemocracy campaign calling for fines to be increased on political campaigners when they breach the rules.

Now, in a new report, the Lords say that the maximum fine for a breach of the laws of British democracy should be half a million pounds, or 4% of campaign spend, whichever is bigger.

The reform is one of a number of demands in a Democracy and Digital Technology Committee report, which warns that reform is vital to help restore public trust in key institutions and ensure UK democracy does not 'decline into irrelevance'.

It claims “unaccountable” firms such as Google and Facebook, have been able to profit from misinformation that can harm both individuals and wider society.

“When they are shown to negatively influence public debate and undermine democracy”, the digital platforms should be held responsible, according to the report's authors.

The probe follows widespread public concern over the way digital platforms have allowed political campaigners to use data to 'target groups of voters with highly-tailored messages which may not be open to public scrutiny or make it obvious who is paying for them.

Repeated breaches of electoral laws during the Brexit referendum campaign and the 2019 general election have also prompted calls for reform from parliamentarians, regulators and campaign groups.

The Lords committee proposes that, for the first time, political advertising should be subject to the same rules on accuracy and truthfulness as other types of advertising. Platforms should also be forced to provide more information on the funders and targeting associated with digital campaign ads.

A new code should be backed by a new ombudsman that could force digital platforms to moderate content judged ‘harmful’ to the public, whilst the Lords have backed proposals from the Electoral Commission to strengthen its powers to regulate campaign spending on digital platforms.

Other campaign groups have also argued that tech-giants' efforts to bring transparency to UK political campaigning have failed. Open Rights Group has highlighted how simple it is for bad actors to subvert Facebook’s in-house political ad transparency rules, and has called on governments throughout the UK to legislate.

The chair of the committee, Lord Puttnam, said: "We are living through a time in which trust is collapsing. People no longer have faith that they can rely on the information they receive or believe what they are told. That is absolutely corrosive for democracy.

"Part of the reason for the decline in trust is the unchecked power of digital platforms.

"These international behemoths exercise great power without any matching accountability, often denying responsibility for the harm some of the content they host can cause, while continuing to profit from it."

In response to the latest Lords report, Electoral Reform Society campaigners have insisted that the UK Government must now take action, describing progress on modernising UK electoral laws to date as “woeful.”

Darren Hughes, chief executive of the Electoral Reform Society, said: “Despite countless regulators, campaigners and committees calling for action, there has been woeful inaction from the government when it comes to updating Britain’s analogue-age campaign rules.

“The government has promised to implement transparency for online political ads. This should be implemented before next year’s major round of elections. ‘In due course’ is not good enough."

Following the release of the report Lord Puttnam, told the BBC that the UK government may not bring in legislation regulating digital platforms until 2023 or 2024 – seven years after new laws were first proposed.

The government has reportedly said that legislation would be introduced "as soon as possible".