It's official: a pint of Guinness in London has broken the £6 mark. With the big smoke now officially the most expensive place for a pint of the black stuff, where should you be ordering Guinness in Britain this St Patrick's Day?

Across Britain, the average cost of a pint of Guinness is £4.78, according to research by
UK Debt Expert.
The financial services firm looked at the cheapest and most expensive places in Britain for a pint of Guinness in the run up to St Patrick's day on Monday, and found that the average price was up 5% from last year.
The average pint of Guinness has broken the £6 mark in London, at £6.42, making it the most expensive pint in Britain. This is a 12% increase on last year.
Londoners can also expect to pay more than anywhere else for the Irish stout's alcohol-free alternative, Guinness 0.0, with a pint can (538ml) costing £4.92 on average in the city - 3% more than the UK’s average pint of Guinness.
UK Debt Expert looked at the cost of a pint of Guinness in hundreds of pubs across the UK to reveal the cheapest and most expensive places for a pint of the Irish stout, with the average setting punters back 30p more than this time last year.
Bolton was revealed as the cheapest British city for a Guinness, where a pint will set drinkers back around £4.17.
Here's the list of the 10 cheapest cities in the UK for a pint of Guinness on St Patrick's Day:
Bolton - £4.17
Stockport - £4.27
Swindon - £4.28
Gloucester - £4.30
Derby - £4.35
Stoke-on-Trent - £4.36
Rotherham - £4.37
Sunderland - £4.38
Hull - £4.40
Nottingham - £4.42
...and the 10 most expensive:
London - £6.42
Edinburgh - £5.66
York - £5.43
Cambridge - £5.36
Oxford - £5.08
Reading - £5.05
Brighton - £4.99
Watford - £4.97
Glasgow - £4.93
Portsmouth - £4.91