Question: My position was eliminated two years ago in a downsizing. I took a related stop-gap job, but much lower level and less enjoyable. A year later, I went to a direct competitor of my first company, taking on twice as much work as I expected. I failed and was terminated after six months. Now my former supervisor at my first company is apparently saying negative things about me to prospective employers. What should I do?

Answer: Job seekers have several options that can help them to overcome a bad reference from a former manager, and I'll get to them. But you have bigger problems because of your career missteps since the downsizing.

Employers don't like to take risks when hiring new employees. They're often willing to overlook one blemish or error in an applicant's career, but not a series of them, says Annaly McPherson, director of human resources for Zetron Inc., a Redmond, Wash., communications company.

"Employers are very picky, and they want people with outstanding references who can come in and do the job," says Ms. McPherson.

You have three strikes against you: the layoff; your decision to take a lower-level job; and the firing. That's a lot of explaining to do.

Some job seekers chalk up a string of career missteps to simple bad luck. This means they don't have to look at their part in what happened. You need to take the high road and ask yourself what led you to make your career decisions since the downsizing and what you might have done differently.

"In the end, you are your own best reference," says Ms. McPherson. "Sometimes when bad things happen in a row, you have to say, 'What part of this do I own?' "

Many employers find honesty refreshing. Briefly acknowledging your recent mistakes and what you learned from them may impress some hiring managers. But it may not be enough. You may need to switch industries or make another type of professional shift that will allow you to rebuild your career on a new foundation, Ms. McPherson says.

But if you didn't have these other complications, the first step to combating a negative reference from a former boss is to confirm if your suspicions are true. Consider hiring a reference-checking service, which will try to contact the former boss to learn what he or she is saying about you.

Typically, the service will ask about your employment dates and titles and then whether the manager would recommend you, says Mary Hunter, vice president of JobReference.com, a New Jersey-based service.

You'll receive a report in three to five days about the conversation, plus descriptions of the supervisor's tone and demeanor, Ms. Hunter says. "If a manager is abrupt and offensive, we document it in the report." (The service also will report if its request was forwarded to human resources, which normally confirms only a prior employee's employment dates and job titles.)

If your former supervisor is indeed saying negative things about you, be ready to do immediate damage control during your next interview. Explain that your former manager and you didn't see eye to eye and that this boss might say uncomplimentary things about you. Then address how you have dealt with any problems that existed.

"Honesty may actually turn things around for applicants who can acknowledge shortcomings and explain the steps they have taken to improve themselves," says Julia Tompson, president of References-etc Inc., a Gorham, Me., reference verification service.

Another tactic is to explain in general terms why you and your former boss didn't get along, says Ms. McPherson. You might say, for instance, that your goals or the way you wanted to achieve them were different and that the fit wasn't right, she suggests. "Then swiftly offer references from people at that company who thought highly of you," she says.

Ask another manager who knew your work at your former company if he or she might be willing to speak on your behalf. Former co-workers also might be willing to provide a recommendation. Typically, they're twice as likely to provide good references than former supervisors, although their words may carry less weight, says Ms. Tompson.

If your former manager is making negative comments that are false or baseless, consider calling or sending a letter asking him or her to stop. "Sometimes the mere threat of a lawsuit can zip the lips of a former employer," says Ms. Tompson.