London (CNN) -- British lawmakers investigating a phone hacking scandal Tuesday asked media baron Rupert Murdoch, his son James and former News of the World editor Rebekah Brooks to testify before them, hours after former British Prime Minister Gordon Brown accused their newspaper group of illegally obtaining private information about him.

Parliament's Culture, Media and Sport Committee asked the three to appear in a week, on July 19, a representative told CNN.

"Senior executives" of Murdoch's British newspaper company "will cooperate," News International said in a statement, without specifying who.

If the Murdochs and Brooks do not answer the summons, Parliament can compel them to do so, Labour lawmaker Chris Bryant said on Twitter. He added that he believes he too is a hacking victim.

The chairman of the committee, John Whittingdale, told CNN that he has plenty of questions to ask. "The first thing is that James Murdoch has said he has discovered that Parliament, and that means my committee, was misled by some of the executives who have given us evidence in the past," he said. "So we will obviously want to know who has misled Parliament and what it was they said which was untrue."

Meanwhile, a Downing Street source told CNN the British coalition government will vote in favor of a parliamentary motion by the Labour opposition calling on News Corp. to withdraw its bid for satellite broadcaster BSkyB.

Whittingdale predicted any vote would be lopsided, if not unanimous, against the elder Murdoch. "I would have thought that, if Parliament sends a signal as strong as is likely, he would be very foolish to ignore it."

Officials must first establish who authorized the "very serious criminal activities" under scrutiny, Whittingdale said. "Anybody who was complicit in that, who knew about them, potentially is vulnerable."

The news represents a further threat to Rupert Murdoch's plans to create Britain's largest media company by acquiring the satellite broadcaster. News Corp. has been seeking to buy the 60.9% of the BSkyB shares it does not already own.

Labour leader Ed Miliband and Deputy Prime Minister Nick Clegg are among lawmakers who have already urged Murdoch to reconsider the bid.

Brown, speaking Tuesday to the BBC about allegations that The Sunday Times illegally obtained private information about him, accused Murdoch's newspapers of having "links with criminals."

Brown said the paper appeared to have gotten access to his legal files. He said he was "genuinely shocked" by its methods.

The Sunday Times denied Brown's allegations and said it pursued the story about him in the public interest.

"We were told that Mr. Brown had bought a flat cheaper than any normal valuation and that he obtained it through a company in which Geoffrey Robinson, a close ally, had been a director," it said Tuesday in a statement.

"We had reasonable grounds to investigate this matter ... We believe no law was broken in the process of this investigation, and contrary to Mr. Brown's assertion, no criminal was used and the story was published giving all sides a fair hearing."

Brown's allegations, however, widen the scandal that brought down Britain's best-selling newspaper, News of the World, to other newspapers also owned by Murdoch's News International media group.

Suspicions that News International would fill the Sunday tabloid gap by publishing its six-day-a-week tabloid The Sun on Sundays were reinforced by the company's acquisition on Monday of the domain name thesunonsunday.co.uk.

News International's parent company, News Corporation, announced Tuesday it would buy back $5 billion of its own shares over the coming year, after a fall in its share price since the phone hacking scandal exploded last week.

Top Metropolitan Police officers testified before lawmakers Tuesday about their investigation into illegal breaches of privacy by News of the World, following accusations police did not probe deeply enough when they first looked into matter.

Assistant Commissioner John Yates, who concluded in 2009 that there was not enough evidence to pursue an investigation, admitted to the Home Affairs Select Committee that his decision was "crap."

And he said he believed his own phone had been hacked "in the period 2005-2006."

He blamed News International for not handing over all the documents they had.

But lawmakers hammered his decision.

"Why did you not look at the information that was sitting in bags at Scotland Yard?" demanded conservative lawmaker Michael Ellis.

Yates insisted he had "never, ever, ever" received a payment from a journalist, but said it was "highly probable" that there were some corrupt officers among the 50,000 in the Metropolitan Police.

News International is accused of attempting to bribe police officers for information -- including personal contact details for members of the royal family -- in addition to the violation of privacy allegations.

Yates said he did not see Gordon Brown's name on a list of potential hacking victims when he examined the evidence police had in 2009.

The accusations that journalists working for News International papers went after Brown were published Monday by rival outlet the Guardian.

The Guardian said the tabloid The Sun -- the country's best-selling daily newspaper -- obtained details about Brown's son's health and published a story about him, while people working for the broadsheet Sunday Times tricked the former Labour Party leader's accountants into handing over financial details.

Both papers are part of the News International stable. The company denied that The Sun illegally obtained information about Brown's son.

"We are able to assure the Brown family that we did not access the medical records of their son, nor did we commission anyone to do so," News International said in a statement.

It said its story about Brown's son "originated from a member of the public whose family has also experienced cystic fibrosis" and wanted to highlight the plight of those afflicted with the disease.

"The individual has provided a written affidavit this afternoon to a lawyer confirming this," the statement said.

The efforts to obtain information about Brown and his family dated back some 10 years, and include periods when Brown was prime minister and chancellor of the exchequer, according to the Guardian.

Brown declined several CNN requests for an interview about the allegations.

The latest allegations follow Sunday's closure of the News of the World over other allegations of illegal breach of privacy.

The decision to pull the plug on the 168-year-old paper came amid accusations that its reporters illegally eavesdropped on the phone messages of murder and terrorist victims, politicians and celebrities, as well as claims it may have bribed police officers. Police said Thursday they had identified almost 4,000 potential targets of phone-hacking.

London's Metropolitan Police Monday angrily blasted leaks from its investigation into illegal eavesdropping by News of the World, shortly after British media reported that the paper tried to bribe royal protection officers to get private phone numbers for members of the royal family.

Police said News International had shared information about alleged efforts by reporters to bribe police, and that both sides had agreed to keep the information confidential.

Police said they were "extremely concerned and disappointed" at the leaks, which they said "could have a significant impact on the corruption investigation."

Police, the royal family and News International all refused to answer CNN questions about allegations that a reporter sought company money to pay a royal protection officer for the confidential details about the royal family.

The controversy over phone hacking has continued despite the shuttering of News of the World. Murdoch has not apologized to the family of a murdered British teenage girl whose phone messages were illegally intercepted, a lawyer for 13-year-old murder victim Milly Dowler's family said Monday.

Brooks has been promoted to chief executive of News International, and Murdoch has stood by her.

Murdoch flew Sunday to London, hours after the final edition of News of the World hit the stands. The publication was the first British national paper Murdoch bought, in 1969, as he began to propel himself from Australian newspaper proprietor to international media magnate.

With its closure, News International now owns the Sun, The Times and The Sunday Times in Britain.

Murdoch's News Corporation also encompasses Fox News, The Wall Street Journal, the New York Post and Harper Collins publishers.

CNN's Jim Boulden, Andy Carey and Dan Rivers contributed to this report.