Cahill files lawsuit alleging dirty political tricks in Mass.

Cahill's attorneys asked  the court for an immediate restraining order to prevent Weaver, a well-known national Republican political strategist, Meldrum, Yob, and former political director Jordan Gehrke, from giving any confidential information and documents to Baker and the Republicans.

Superior Court Judge Barbara A. Dortch-Okara today granted the temporary restraining order, barring the four defendants from disclosing any information they may have obtained by working for Cahill until a full hearing Wednesday, with lawyers for the former aides present.

Cahill lawyer Joseph Demeo had urged the judge in a 15-minute hearing to grant the injunction, saying any leak of strategic information "could be devastating to the Cahill campaign."

The suit says the defendants possessed critical strategic information, including fund-raising plans, advertising schedules, and messaging tactics planned for the final weeks of the race. Until their departure from Cahill's campaign, Weaver was working with Yob under an arrangement that had paid Yob's firm at least $213,540 since March.

"The defendants ... knew (and know) essentially everything there was to know about the campaign's strategy and tactics for the final push to the election," the suit says.

When they left, the suit says, Weaver and Yob promised Cahill "that neither of us would go to work for his opponents."

"Even as they made that promise, however, they were actively preparing to break it," says the suit, which accuses the four former aides of breach of contract and unfair and deceptive trade practices.

In a statement, Cahill said "recent events of this race have confirmed the very reason why I left the party system in the first place: Party leaders will go to any length to advance their own interests. Their selfish and questionable actions have resulted in nothing but disappointment from the voters of our Commonwealth time and time again."

Cahill also accused Democrats of "backroom deals," but he directed most of his fire at Baker, saying, "Charlie Baker and his Republican cohorts have been plotting to undermine the integrity of this race in an attempt to mislead the voters."

"On the campaign trail, Charlie Baker has been preaching that there are two sets of rules, one for regular people and one for people on Beacon Hill," he continued. "Well it is clear now that Charlie lives by the very insider rules he so conveniently speaks out against."

Cahill, after speaking at a Hingham retirement community this afternoon, declined to comment further. He canceled the rest of his scheduled campaign appearances for the day.

Asked repeatedly today for comment on the lawsuit, or on overtures his staff allegedly made to seek information on Cahill, Baker, who is campaigning north of Boston, said, "I don't know anything about it."

Baker also said he had not authorized anyone in his campaign to make overtures to the former Cahill aides to get inside information.

His campaign later released a statement, saying, "So far as we can tell from media reports, Tim Cahill has filed a lawsuit to prevent public disclosure of emails that indicate his campaign may have been illegally coordinating with state employees at the Treasury. We did not receive any written internal information regarding the Cahill campaign, period, but call on the treasurer to come clean about improper activities in his campaign rather than trying to cover them up through a lawsuit."

The suit bases its allegations on email communications it obtained, in which Weaver, Yob, and Meldrum -- along with Loscocco confidant Jason L. Zanetti, a Boston lawyer and lobbyist -- discussed the best way for Loscocco to leave the ticket and, after he did, deciding several days later to give sensitive information to both Baker's staff and the RGA. The emails were obtained by the Cahill campaign from Meldrum's personal and official campaign accounts, both of which were routed through the Cahill campaign server.

''I spoke with Tim O'Brien just now,'' Zanetti wrote to Weaver, Yob, and Meldrum in an email sent last Sunday afternoon, just two days after Loscocco's press conference, according to the lawsuit. ''He wants to let the Paul story die on the vine. I wouldn't mind at least one discussion with Adam and a reporter though about the 'deep divisions' between the camps, disrespect/distrust of Paul/his team, etc.''

The email continues, ''the Baker folks would really appreciate any 'hard evidence' emails/documents that shows improprieties ... Adam and I just spoke and he has some stuff. I think we should give them everything we have.''

Zanetti, according to the suit, also wrote of Cahill's campaign, "I know there were lots of state employees doing political stuff when they shouldn't have been but we need proof.'' Zanetti then referred to the public reaction to Loscocco's abrupt departure form the campaign. ''We want to stop the 'sympathy' that this is generating" for Cahill, he wrote.

Baker and his staff have strongly denied pressuring Loscocco to leave Cahill's side or offering any enticements, such as a future job in state government. None of the emails in the lawsuit contradict that denial, though they suggest the Baker campaign was actively seeking internal information about Cahill and his campaign that Cahill's departing aides possessed.

Weaver, a former top political adviser on John McCain's presidential campaigns, quit the Cahill campaign on Sept. 23, apparently along with Yob. Meldrum resigned the next day. The departures came as polls showed Baker moving closer to Governor Deval L. Patrick in the battle for the lead in the race, with Cahill stuck deep in third place.

At one point, the suit alleges, Weaver instructed Meldrum to contact a RGA staff member, identified as Dennise Casey, and "follow through" with ''the emails and other things you have re: cahill and coordination with lottery and ties to Patrick.''

According to the suit, Meldrum immediately contacted Casey. "The urgency with which the defendants and the RGA viewed the process of extracting information about the Cahill campaign from the defendants is illustrated by the fact that Nick Ayers at the RGA then instructed Weaver to 'have Adam and Dennise coordinate so I don't slow things down.'''

As a reward for resigning from Cahill's campaign, the suit alleges, Meldrum was given a job by the RGA working on a campaign in New Mexico.

The suit also contends that Zanetti worked closely with Weaver and his associates to get Loscocco off the ticket. It says that Weaver, Yob, and Meldrum discussed the political risks and benefits Loscocco would face if he departed.

Noah Bierman and Andrew Ryan of the Globe staff contributed to this report.