Washington (CNN) – A rare sighting of three U.S. presidents at the White House will happen Thursday when George W. Bush and his father, George H. W. Bush, join current President Barack Obama for the unveiling of the younger Bush’s official portrait.

The leaders past and present, as well as their wives, will have a private lunch together before the unveiling ceremony for the portrait of the nation’s 43rd president. A portrait of former first lady Laura Bush also will be unveiled.

Bush has mostly kept away from Washington and the White House since leaving office. His spokesman, Freddy Ford, said this month that the Bushes “are looking forward to seeing a lot of their friends from the administration and they are grateful to the president and first lady for their hospitality.”

Obama has blamed his predecessor’s administration for leaving the nation in economic shambles, and he now accuses his certain Republican opponent in November’s election — Mitt Romney — of advocating the same failed policies.

However, tradition and presidential etiquette suggest that no politics will come up at Thursday’s ceremony.

On Wednesday, White House spokesman Jay Carney referred to former presidents as “a community … with very few members that transcends political and policy differences.”

“There are differences there without question between (Obama’s) approach and the approach and the policies of his predecessor,” he said. “That was certainly the case when I believe President George W. Bush had President Clinton to the White House for his portrait unveiling, and I think it is well established that those two now former presidents have a good relationship, as did President Bill Clinton with President George H.W. Bush.”

He added: “… There is so much shared experience between … the men, and one day the men and women who hold this office that there is much to talk about that … they hold in common. So there’s not a lot of need to talk about where they differ.”

There are two other surviving former presidents: Clinton and Jimmy Carter.