This article is by Don Van Natta Jr., Graham Bowley and Jo Becker.

LONDON — After his testimony in Parliament was challenged by two former senior employees and referred by a lawmaker to Scotland Yard for investigation, James Murdoch has come under rising pressure in Britain’s phone hacking scandal that is likely to intensify this week.

The board of British Sky Broadcasting, the satellite broadcaster of which Mr. Murdoch is chairman, convenes on Thursday for the first time since the scandal erupted, as regulators continue their inquiry into whether the hacking scandal means the broadcaster should continue to be considered “fit and proper” to hold a broadcasting license. A day later, members of the parliamentary committee investigating the scandal are to meet to consider whether to ask for more information from Mr. Murdoch and whether to call him and former executives back in front of them to answer additional questions.

Some former senior executives of News International who until recently held powerful positions in the News Corporation’s British subsidiary and were privy to internal deliberations have indicated that they believe Mr. Murdoch knew more about widespread phone hacking at The News of the World than he indicated in his public testimony. If they continue to challenge Mr. Murdoch’s account, it could damage his effort to protect his own reputation and that of the parent company run by his father, Rupert.

“It now seems to be everyone for themselves,” said Paul Farrelly, a Labour member of Parliament who has been a prominent critic of News International. “The edifice is cracking; they’re all fighting like rats in a sack.”