Not knowing the ins-and-outs of a job and lacking enthusiasm are among the top job interview howlers, according to graduate recruitment and sales training firm Pareto Law.

Other errors often made include giving too much intimate information. One candidate said he smoked weed when asked what he did in his spare time, and another said a threesome was his greatest achievement.

Another interview mistake is not preparing questions for the end of the interview. One candidate, when asked if she had any questions, replied: “Are you going anywhere nice on your holidays this year?”

Also key is dressing smartly. Pareto Law says one candidate turned up for an interview wearing flip-flops and a t-shirt.