Updated

Former Charlotte Mayor Patrick Cannon was expected to plead guilty Tuesday in a corruption case after an FBI sting recorded him accepting thousands of dollars in cash and airline tickets from undercover agents posing as businessmen, according to court documents.

Cannon agreed to plead guilty to a single count of honest services wire fraud, which carries a sentence of up to 20 years in prison and a $250,000 fine, according to documents filed Monday at U.S. District Court. Cannon was set to appear Tuesday before U.S. Magistrate Judge David Cayer.

Cannon, 47, was arrested March 26 and the Democrat resigned the same day, less than six months after taking office. Cannon's lawyer, James Ferguson of Charlotte, did not immediately respond to a message left at his office.

Cannon's admission of guilt ends a remarkable rise for a man raised by a single mother in one of the city's poorest neighborhoods. He went on to start his own company that manages 25,000 parking spaces, mostly in the city's central business district.

Cannon was first elected to the City Council in 1993 and became mayor in November, replacing Anthony Foxx, who was named Transportation Secretary by President Obama.

According to the federal criminal complaint, Cannon accepted more than $48,000 in cash, airline tickets, a hotel room and the use of a luxury apartment from FBI agents posing as real estate developers who wanted to do work with North Carolina's largest city. Cannon is also accused of soliciting up to $1 million more in bribes from the undercover agents.

If he had been convicted on all charges at trial, Cannon faced up to 50 years in prison and more than $1 million in fines.

The investigation began in August 2010 after a tip from a local undercover officer about public corruption. At the time, Cannon was a city councilman.

The complaint said Cannon bragged to agents about his close relationship with former Charlotte mayor and current North Carolina Gov. Pat McCrory, as well as a recent meeting he had at the White House with Obama. In exchange for the bribes, the mayor promised the undercover agents access to city officials responsible for planning, zoning and permitting, according to the complaint.

On the last occasion, a private meeting in the mayor's office on Feb. 21, the agent reportedly gave Cannon a briefcase filled with $20,000 in cash.