get your IRATA level 1, (about £800) then try a firm called Shadbolt Roped Access, I think they take on level 1's. As a level 1 you can only work alongside a level 2 or 3, you can't work alone or with another level 1.
1000 hours and another £800 training session gets you a level 2. thats when you can work on your own.
To be fair you can earn more on pole work. lots more!