Kevin Ring’s defense team made its opening salvo Thursday as the former House-aide-turned-lobbyist faces a retrial on public corruption charges. Defense attorney Andrew Wise urged jurors to be skeptical of witnesses who accepted plea bargains in the investigation that centers on former lobbyist Jack Abramoff.

Wise also instructed jurors to pay attention to the full text of e-mails expected to be offered as evidence by federal prosecutors, asserting that the highlighted exchanges amount to little more than “bravado” and “bragging.”

“The evidence will show this is a case based largely on overstatement [and] exaggeration,” Wise said.

Ring was indicted in 2008 on charges stemming from the investigation of Abramoff, his former boss.

Federal prosecutors allege that Ring’s pattern of providing tickets to sporting events and other gifts to Congressional staffers in exchange for assistance for Abramoff’s clients amounted to illegal gratuities.

Ring has denied wrongdoing, and his defense argued Thursday that he acted within the laws in place at the time of the allegations between 2002 and 2004.

“It was part of legal lobbying,” Wise said. He told the jury that Ring did not violate federal laws during his tenure as a lobbyist but rather acted within legal limits to curry favor with public officials.

“A gift given to or offered to cultivate a relationship is not an illegal gratuity,” he added.

Wise also encouraged the jury to be critical of testimony from several witnesses expected to be called by federal prosecutors, including some of Ring’s former colleagues.

“The evidence will show that memories are changing and stories are evolving,” Wise said, noting that government witnesses have held numerous meetings with prosecutors in recent years.

Wise focused extensively on Neil Volz — the former chief of staff to ex-Rep. Bob Ney (R-Ohio) — who is expected to testify Monday.

Although Volz pleaded guilty in 2006 to helping Abramoff bribe Ney and was sentenced in 2007 to two years of probation, Wise asserted that Volz could still have his own motivation for providing testimony, highlighting what he called Volz’s “very public image reclamation project.”

Wise noted Volz’s media interviews in recent months and his appearance in the documentary “Casino Jack and the United States of Money.”

Federal prosecutors offered their opening arguments Thursday morning, portraying Ring to the jury as a “corrupting” influence on Capitol Hill.

“This is a case about a team of lobbyists who tried to corrupt the political system,” prosecutor Nathaniel Edmonds said. He later added: “The defendant’s actions were not just lobbying, they were corruption. … They were crimes.”

Ring’s first trial occurred in the U.S. District Court for the District of Columbia in 2009, but Judge Ellen Huvelle declared a mistrial when jurors failed to reach a unanimous verdict.