Mississippi Sen. Thad Cochran isn’t returning to Washington this week after all, due to illness. Some fear his absence may continue, causing problems for Senate Republicans who need his vote to fulfill promises on tax reform.

Cochran’s staff had announced he would return this week, rejoining the Senate Monday when it returned from recess.

But Cochran’s chief of staff Brad White announced today that Cochran, 79, will not return as planned because he is dealing with a urinary tract infection that has returned.

Cochran, a Republican, is needed in Washington as the party, controlling the Senate, hopes to pass a budget item that is vital to rewriting the tax code.

White reported in the announcement that Cochran’s wife told him late Saturday that the urinary tract infection had returned, the Associated Press reported today.

Cochran’s Twitter account revealed a photo of him late Friday visiting with his brother. Cochran has been recovering for several weeks from a urological procedure, according to reports.

Some wondered if that Tweet was a response to a Politico article last week that questioned whether Cochran’s illness was more serious than aides were reported.

Politico said “multiple sources close to the senator said his staff and allies have received limited information from his family about his health status, further fueling questions about his future.”

Cochran’s spokesman said, however, that Cochran has every intention of returning to Washington.

“After a day of monitoring his condition, and on the advice of his physicians and other health care professionals, Senator Cochran has postponed his return to Washington. He will continue his recuperation at home in Mississippi,” White said, according to the AP. “The Senator has expressed his intention to return to the Senate when his health permits, and to fulfill his commitment and duties to the people of his state.”

Cochran leads the Senate Appropriations Committee as chairman so his absence will be felt. “The panel had planned to vote on a key homeland security spending measure this week, with a showdown anticipated over spending for a down payment on President Donald Trump’s promised wall along the U.S.-Mexico border,” the AP reported. The measure is now shelved.