VIDEO: 'Embarrassed and humiliated' New Jersey Governor apologises for bridge scandal

An "embarrassed and humiliated’’ New Jersey Governor Chris Christie has sacked a top aide in response to a mushrooming scandal that has the potential to thwart one of the US Republican Party's greatest hopes for the 2016 presidential election.

Mr Christie, a Republican, sacked his deputy chief of staff after emails revealed that aides in his office had closed down lanes on the George Washington Bridge in September, apparently to punish the people of Fort Lee after its Democratic mayor, Mark Sokolich, refused to endorse the Governor in the recent state election.

The lane closure caused massive traffic jams for four days that stalled commuters, school buses and ambulances in hours-long delays on the bridge that links New York to New Jersey.

The scandal, which exposed a stunning level of spite in the Governor's office, has continued to spiral out of control for Mr Christie. 

"I come out here to apologise to the people of New Jersey," Mr Christie said during a press conference. "I am embarrassed and humiliated.”

The US Attorney's Office for the District of New Jersey has opened an inquiry into claims that public officials orchestrated the massive traffic snarl on one of the busiest bridges in the world for political payback, while a key Christie ally has refused to answer questions in testimony.

"The Port Authority Office of Inspector General has referred the matter to us, and our office is reviewing it to determine whether a federal law was implicated," Rebekah Carmichael said in a statement.

Mr Christie said he had sacked his deputy chief of staff, Bridget Kelly, and ordered his campaign manager and close friend Bill Stepien to take his name out of contention from running the New Jersey Republican Party.

"I had no knowledge or involvement in this issue, in its planning or its execution," Mr Christie told reporters.

"I've terminated the employment of Bridget Kelly, effective immediately. I terminated her employment because she lied to me," Mr Christie said.

"I am responsible for what happened. I am sad to report to the people of New Jersey that we fell short."

During the press conference, Mr Christie said he was blindsided by the emails. He said while it was true he was a tough, straight-talking politician, his reputation for micro managing was incorrect.

Emails showed his staff plotted the four-day lane closures at the bridge.

Already two of his senior appointees to the Port Authority, which controls the bridge, have resigned and hired lawyers.

David Wildstein, a high school friend of the governor who worked at the Port Authority, resigned on December 6, saying that the bridge issue had become “a distraction” for the Christie administration.

Mr Wildstein had challenged a subpoena from the State Assembly demanding he appear at an inquiry on the matter. A judge on Thursday ruled that the subpoena was valid and he appeared before the legislature later in the day. He declined to answer questions.

Mr Christie had maintained his claim that his office had nothing to do with ordering the closures until Tuesday, when a local paper, The Bergen Record, published the emails from Ms Kelly to Mr Wildstein, one of which, on August 13, said: “Time for some traffic problems in Fort Lee.”

He replied, “Got it.”

The lanes on to the bridge were closed a fortnight later on the first day of the new school year, causing days of traffic chaos for the people of Fort Lee.

The Fort Lee mayor was not advised the lanes would be closed.

In other emails released on Tuesday, members of Mr Christie's staff appeared to joke about the impact of the closure.

On September 10, Mr Wildstein texted Ms Kelly: "Is it wrong that I am smiling?"

Mr Christie and his senior staff had been defending the closures as part of a traffic study.

A legislative inquiry into the closures continues.

Political watchers are wondering whether the Republican Party has just lost its potential number one contender for the White House in the post-Obama era.

- with New York Times, AFP, Reuters

New Jersey Governor Chris Christie apologises during a press conference for the actions of his staff that led to traffic chaos.

New Jersey Governor Chris Christie apologises during a press conference for the actions of his staff that led to traffic chaos.