Thoreau wrote "That government governs best that governs least." In accord with posts #2 and #3, more of the same is not needed. What is needed are people such as those in the early days of America, when people had personal integrity and actually believed in their ideals, and they could not be bought, not another funded party. Today, decisions are political and based on greed--no matter which party.
More parties and politics and government funding of any kind make me nervous--mostly because the two major parties we have are now monstrous in size and distorted in vision. The terms "Republican" and "Democrat" are labels many candidates (and many of the rest of us, frankly) are trying to shed. We do still live under a system which virtually forces us to take on one name or the other (which is undoubtedly why the number of "Independents" has grown), but there is a move toward concepts and ideals as identifiers, things like "Conservative" and "Progressive" and "Fiscally Conservative." Why these delineations? Because the larger term, like the party, is almost so broad as to be meaningless. I know this system makes for an obvious mandate regarding our elected officials (as opposed to 3 or 4 viable candidates where the winner receives only a third or so of the votes), but less is more when it comes to government funding, as far as I'm concerned.
Do you mean more than just the Republican and Democratic parties? Below is a link to a commentary about America under these two parties. Read the commentary and then you tell me whether you want more of the same.
When I say more of the same, I mean that more government funding of additional parties would only create more parties just like the two that we already have. And make no mistake, they do get big chunks of money from the government. They get bigger chunks from big business, but in America, where is the line between government and big business? And to be fair, they also get money from contributions by middle-class people (many of whom make their living through provision of services to big business).
We would have an easier time giving you a good answer if you would specify what country you are talking about. In the United States, we have two parties, but they are not funded by the government. So it seems to me that you aren't talking about the US. If you said which country, I might be able to talk about that country's specific situation.
In general, here is the trade-off that you face when deciding whether to have two parties or more than two. If you have two parties, you have more people who are dissatisfied with their party. The parties have to try to move towards the middle of the political spectrum. They have to compromise so as to attract lots of people to their party. This means they cannot be "pure" on many issues and that angers people who want purity.
If you have many parties, you can have more purity on issues. However, you give up some ability to compromise. You get people who are more of zealots on a particular issue. Their party is formed around that one issue and it has trouble caring about other issues and it has trouble compromising on that issue so as to get along with other parties.
So the choice is between ideological purity and compromise -- which do you think is better for parties to do?