Anna Burger, the former number two at the Service Employees International Union (SEIU), has joined the board of directors at the Center for American Progress Action Fund.

In a statement, John Podesta, chairman of the board, said the group was "pleased" that Burger was coming on board.

"She has been a longtime friend of the Center for American Progress and CAP Action and we’re very happy that she has agreed to help us advance our mission by serving in this new capacity. Anna Burger has been fighting hard for progressive ideas and policies for nearly 40 years, including the visionary leadership she has provided for the progressive movement over the past decade," Podesta said.

The action fund is an affiliated advocacy group of the Center for American Progress, a liberal think tank.

The think tank is considered to be close to the White House. Podesta was in charge of President Obama's transition team after the 2008 election. Several of the think tank's employees have since joined the administration.

Burger recently retired from SEIU, where she served as secretary-treasurer.

After long-time SEIU President Andy Stern left his position earlier this year, Burger made a bid for the top spot. She dropped out of the race though once Mary Kay Henry secured enough support to win the presidency.