WASHINGTON, (Reuters) - Federal health officials have not followed through on a promise made last year to improve the safety of the U.S. food supply, lawmakers and others said Thursday, as investigators work to determine the extent of the latest foodborne illness linked to tomatoes.

In the past week, a rare strain of Salmonella has sickened 167 people in 17 states who ate certain types of tomatoes.

This is the latest in a series of incidents that have eroded public confidence in the safety of the food supply and lead to more calls for change at the Food and Drug Administration. There also have been problems with lettuce, peanut butter and spinach in recent years.

"These continued outbreaks are unacceptable," said Rep. John Dingell, chairman of the full House Energy and Commerce Committee. "To have (the FDA) come up and say they don't know what to do about it or how much money they need or what resources they require is a shame and a disgrace."

Last November, the FDA, which oversees 80 percent of the food supply, issued a "food protection plan" that would focus on preventing problems in the riskiest areas before they occur, both domestically and overseas, rather than simply conducting more inspections and testing.

Since then, FDA has been criticized for failing to outline a clear strategy and the cost of carrying it out.

The Government Accountability Office said in January

the plan may falter unless FDA offers more details. And FDA's Science Board, an advisory panel to the agency, has said the FDA does not have the capacity to ensure the safety of the food supply.

"As foodborne illness outbreaks continue, FDA is missing valuable opportunities to reassure Congress and the public that it is doing all it can to protect the nation's food supply," Lisa Shames, a GAO director on food and agriculture, told a House Energy and Commerce subcommittee.

The concern has lead Democratic lawmakers to hold dozens of hearings to review the FDA and encourage it to request additional funding to help improve the safety of the nation's food supply. This week the Bush administration requested an additional $125 million for food safety on top of the $42 million it was already seeking for fiscal year 2009.

Michael Taylor, a professor at George Washington University, said the budget increase was "a downpayment" and echoed earlier calls by the FDA Science Board to double the food safety budget to $1.4 billion by 2013 to institute effective reform.

For now, Taylor said FDA should identify some immediate actions "to begin the shift from reaction to prevention and address some of today's pressing food safety problems." Currently, FDA could identify where the most important food safety problems exist and identify strategies to improve them.

(Editing by Christian Wiessner)