Iirc its an income of less than 60% of the average income - Afaik if a family have in income of less than approx. £1100 per month then they are considered to be in poverty. 
Quite a few people have made quite lucrative careers in the fight against "poverty". 
If thats the case I'm in serious poverty, my wife is on maternity leave £125 p/wk and I'm on incapacity benefit due to my recent knee op, £67.50 p/wk. That equates to roughly £780 p/month.
Yes, things are very tight, but I wouldn't say I'm in poverty. I just can't enjoy everything I'd like to do and have to save a few weeks to go anywhere

I'm desperate to get off incapacity and find a job, but I can't even get work experience

I even offered to do free work to gain experience to help me with my college course, even that was turned down

I have a 2 yr old and baby due anytime now, but neither will go without food or clothing...ever!