Of course it depends on where in the UK, but in major cities the cost of living is some of the highest in Europe.
In Amsterdam (similar to London if not cheaper), you can expect your rent alone to be 1000-1500 Euro for a small apartment. Cost of living (just food and drink) 100-150 Euro per person per week (for decent food, but certainly not high end).
Mandatory health insurance several hundred Euro a month.
Taxes, other insurance, etc.
At an income of 30k pounds a year, or about 3000 Euro a month, before taxes, you can expect to have about 2-300 a month to spend on clothes, hobbies, training, transportation, and luxuries. Not a lot, if you consider a pair of decent jeans can cost you a hundred, a drink at the pub 5 Euro per glass.
That said, it's not a bad income, on the low side of normal in fact.