LONDON, England — BRITISH politicians struck a last-minute deal on press regulation Monday, unveiling new rules that aim to curb the worst abuses of the country’s scandal-ridden media.

The deal, agreed upon by all three major parties, came on the same day a lawyer announced in court that there could potentially be hundreds more hacking victims of Rupert Murdoch’s media empire.

Victims’ groups had lobbied for an independent watchdog whose powers are rooted in legislation, while media groups had opposed any potential press law, saying it threatens press freedom.

After months of political wrangling, the new deal is a complicated compromise. Politicians touted it as a victory, but critics are skeptical — and many uncertainties still remain about whether Britain’s newspapers are willing to cooperate with it.

The proposals were the result of heated debate in Britain over how to implement the recommendations of Lord Justice Brian Leveson, who was charged with cleaning up a newspaper industry plunged into crisis by revelations of widespread illegality.

Prime Minister David Cameron said the proposals would ensure better media practices, while steering clear of setting down a press law that could restrict the country’s fiercely independent press.

“We stand here today with a cross-party agreement for a new system for press regulation,” Cameron told lawmakers. “It supports our great traditions of investigative journalism and free speech. It protects the rights of the vulnerable and the innocent.”

Explaining why he rejected a new press law, Cameron said: “I believe it would be wrong to run even the slightest risk of infringing free speech or a free press in this way.”

The regulator being proposed by politicians would be independent of the media and would have the power to force newspapers to print prominent apologies and pay fines of up to £1 million (US$1.5 million) if they violated the body’s rules.

Submitting to the regulatory regime would be optional, but media groups staying outside the watchdog’s purview could risk being slapped with extra damages if their stories fall afoul of Britain’s court system.

Rather than be established through a new press law — which advocates of Britain’s media have described as unacceptable — the regulatory body would be created through a Royal Charter, a kind of executive order whose history stretches back to medieval times. A law would be passed to prevent ministers from tweaking the charter after the fact.

It was not immediately clear how many newspapers would cooperate with the proposals. A joint statement issued by several of Britain’s largest newspapers said they were still digesting the news, but noted that early drafts of the charter contained “deeply contentious issues”.

Victims’ group Hacked Off said it believed the deal would go a long way toward protecting the public from fresh media abuses, but many journalists and free speech advocates were still uneasy.

The Paris-based Organization for Economic Cooperation and Development was among those expressing concerns about media freedom, warning that the phone hacking scandal should not be used as an excuse to rein in all print media.

The London-based Index on Censorship called the developments a “sad day for press freedom in the UK” The Sun, Britain’s top-selling newspaper, carried a front page photograph of Winston Churchill next to a 1949 quote in which the British leader described a free press as “the unsleeping guardian of every other right that free men prize”.

The Sun, however, is one of several newspapers that have been caught up in the hacking scandal.

The previous watchdog, the widely discredited Press Complaints Commission, barely bothered to investigate allegations of phone hacking before the scandal broke. Its chairwoman, Peta Buscombe, was sued for libel after she challenged the account given by a lawyer for phone hacking victims. The group’s former ethics adviser, Tina Weaver, was arrested last week on suspicion of conspiring to hack phones.

The new regulator is intended to fix some of the Press Complaints Commission’s weaknesses. Newspaper editors would lose their veto over appointments to the watchdog and outside groups could make complaints.

Lawmakers in the House of Commons approved legislative changes later Monday to ensure newspapers who refuse to join the new regime would be liable for damages. Cameron said the charter would be submitted to Queen Elizabeth II for approval in May.