The largest party?

I was just reading about the Likud vote in Israel today, and aside from all the political issues connected, one thing amazed me - Likud has 193,190 members. Now, I don't know anything about how political parties are organised in Israel and whether that figure refers to paid-up party members (as in Britain) or just registered supporters (as in the US), though the use of the term 'members' implies something closer to the British system than the American one, but it still seems to me to be a very large number, especially considering that Israel's population is just over 6 million (according to the CIA World Factbook) which means that around 3% of Israel's population are members of Likud.

As a comparison, it would mean a political party in Britain or France having something like 2 million members or an American one having 10 million. It makes me wonder if - outside of one-party states and the like - if Likud is one of, if not the, largest parties in the world (proportionally, of course). Of course, a lot depends on how membership is defined - both in Israel and other countries - but even if that figure is just officially registered supporters, it still seems quite large to me, especially in a country with as many parties as Israel.

Off the top of my head, the only party I can think of that might be larger is South Africa's ANC. It clearly gets one of the largest shares of the vote for a party in an active democracy (70% just a couple of weeks ago) and one would expect it to have a membership commensurate with that support, but whether it gets up to 3% of the population (which would equate to well over a million members) I don't know.