When asked on a job application ‘why did you leave your last job?’, how am I supposed to respond?

I agree with the above, you have to play this tactically. The last thing you want to do is slag off your last company regardless of how bad the situation was with your Boss. That can put thoughts into another persons mind that your a trouble causer, etc. Keep it positive, that all the reasons your moving on is to improve you and your prospects. One of the best peices of advice i ever heard in business is to always do your utmost to leave on good terms, even if the jobs was absolute hell and you couldn't wait to get out of the door. Grit your teeth, thank everyone including your boss, say you enjoyed you time, etc and walk out smiling. Your references are only one of many ways that prospective employers can hear about you, telling a Boss to stick his crappy job up his butt can damage you for many years to come.

Don't be negative about it as this could make you come across as negative in general rather than just about that job! You could say lack of opportunities or no career advancement available.

i can tell you that depending on the "public sector" job you are applying for, as long as your answer isn't fired, it's not going to matter as much as you think it will. government employers aren't allowed to be as picky as private companies about who they hire. be careful about putting anything too positive, like "i wanted to explore other opportunities" because that doesn't exactly scream "committed" to your new employer. try to think of something that won't hurt anyone's credibility, isn't a negative, and will actually accentuate a quality in the new job that you really like "i love working with dogs and i just couldn't pass up this opportunity when i saw it advertised" "i'm a people person and i wanted a more service-oriented career" good luck. this part of getting/having a job sucks. btw, your second to last paragraph has exactly what you should say..... i have always wanted to work within the public sector as i believe it would allow me the opportunity to be more involved in contributing to the community, and my last job simply did not provide this opportunity. sorry, that just came to me and i'm too tired to delete everything else i already said.

I think what they want to hear is that you worked well there, gained whatever skills or experience possible, and then felt the time came to move on. Because your fantastic, expanding capabilities became too much for the firm's little bubble etc etc. Basically just blank out the negative, and if asked specifically deny it - remember they won't hesitate to lie to you.

You wanted a better job/change of career

tell the truth without sounding like you are moaning about previous employer your new employer will want references anyway

Agree with comments above about not using negatives etc. Wish to broaden experience and exposure to...(sector/theories/processes?) Need a new challenge - i.e. move from private to public and how this seems to fit in more with your own value base but how you had wanted to gain a broader knowldge bas/experience before finally moving into the public sector so that you could bring some of the positives from the private and resist the negatives? Good luck in your new career and welcome to the underpaid and over worked publicvoluntary sector!