It is, barry The Gambling Act 2005 .s335 " The fact that a contract relates to gambling shall not prevent its enforcement"
Formerly any contract which was related to gambling was unenforceable.The old law was repealed at the behest of bookmakers.Modern big bookmakers may have enormous amounts of clients' credit on their books. They felt a bit aggrieved at not being able to get their money!
This may get rid of the significance, in the old law students' problem, of distingushing between a contract of insurance and one for gambling. (The insurance has 'an insurable interest' )