The second is more common, in my opinion.
'Can you give me a hand..' is even more common, and it is in-between your two examples in terms of politeness.
'Do you mind giving me a hand..' is also common in the UK, and is the most polite way to say this, although it isn't overly polite.. e.g. it is appropriate to use with friends or work colleagues. It is a 'nice' way to ask a favour.