For such a small amount, the fees are likely to eat big time into your profits. And also excludes you from some of the cheaper brokers like Interactive Brokers. Your best shots are probably one of the following...

Hargreaves Lansdown

• fees of 0.45%, up to £45/year. 1.5% commission on FX

IG

• fees of £24/quarter. Can be used as credit. 0.3% commission on FX

AJ Bell YouInvest

• fees of 0.25% on shares/etfs, up to £7.5/quarter (£30/year). 1% commission on FX

Halifax Sharedealing

• fees of £12.50/year flat fee. 1.25% commission on FX

& I imagine all will have an execution cost of ~£5-£15. Might want to consider whether it's worth the fees?