All politicians in India have to be socialists. I don't mean it in a cynical kind of way, they actually have to. The Indian constitution gives you all the democracy you want, as long as you pledge allegiance to socialism.
It's a fascinating little story, something I've been following ever since I've known about it about an year ago, now the matter has been finally brought to the Indian Supreme court's attention. Barun Mitra relates the story. Ajay Shah has more.
I wonder what the situation is in Sri Lanka, it could be the case that's actually similar. The preamble to the Sri Lankan constitution too mentions a Socialism as something which constitutes the country, although I don't know whether the Sri Lankan political parties need to take an oath in it's name.