Do I need a tourist visa if I have a valid business visa?

[xyz1983]

I traveled to London on a business visa back in June 2013, and the visa is a multiple-entry visa valid until December 2013. I want to travel to England for a vacation in October, probably just for a couple of days.

I am a citizen of Nepal and a permanent resident of the US, where I currently live and work.

Do I need to apply for a tourist visa again or can I use the business visa?

Thanks in advance.

[xyz1983]

Some additional potentially relevant information: I'll be traveling with my spouse who's a US citizen.