The big three parties face the strongest challenge yet from smaller rivals in England's local elections.
Voting in England will be held on 3 May
The Green Party said it was fielding 1,400 candidates - a "significant increase" on last time.
UKIP has trebled its number of candidates to 1,000, the BNP has gone up from 350 to 750 and the English Democrats are fielding 102.
About 10,500 council seating are being contested in 312 local authorities, with voting on 3 May.
Parties without representation in the Commons have been gaining support in local and national elections in recent years, as they seek to fill political ground vacated by Labour, the Lib Dems and the Conservatives.
Although they have very different political agendas, the 2005 general election saw UKIP, the Greens and BNP gain more than one million votes between them, or 3.9% of the total cast.
The Green Party has seen a boost in its opinion poll ratings in recent months, as environmental issues climb the political agenda.
Green Party: 1,400
English Democrats: 102
Respect-Unity Coalition: 50
Christian People's Alliance: 5
A spokesman said: "We believe that we can increase the number of Green councillors on the principal authorities from the present 93 to around 120, gaining the party's first representation of a number of new councils in the process.
"We are campaigning for strong results elsewhere that will lead to further gains in the next few years."
The BNP doubled its number of councillors at last May's local elections. It fielded more than 350 candidates and now has 46 seats in England.
It claims to have "punched above its weight" in the 36 council by-elections held since last May, with an average of 15% of the vote in wards where it fielded a candidate.
The UK Independence Party claims to have gained an average of 10.5% of the vote in the seats it contested at last May's elections, although it only has "15 to 18" councillors across England.
The party, which gained 2.2% of the vote at the 2005 general election and has nine MEPs, has traditionally focused its efforts on European and general elections, but is attempting to broaden its appeal beyond its core anti-EU message.
Launching its manifesto earlier this week, party leader Nigel Farage said the party wanted to slash council tax and put power back in the hands of local people.
The English Democrats party, which campaigns for an English parliament and a cut in public spending in Scotland, has increased the number of candidates it has been able to field from 16 last May to 102.
It says it hopes to take control of the local authority in Dartford, Kent, in coalition with a local residents' association. The party also has three councillors in nearby Medway.
The anti-war Respect-Unity Coalition, which has one MP at Westminster, George Galloway, is fielding about 50 candidates, concentrating its efforts in Birmingham, Preston and Luton.
A spokeswoman said the party stood "a good chance in a lot of places", and was confident of raising "awareness" of the party.
The Christian People's Alliance, which described itself as an "exceptionally small party", will have a total of about five candidates - in Rotherham and Northampton.
Across all 36 Metropolitan boroughs, one-third of council seats will be contested.
In 25 unitary authorities the whole council will go to the polls, while in another 20 only a third of seats are up for election. Of district councils, 153 will elect the entire council, another 78 will elect a third.
There are about 100 smaller parties standing, as well as independents.
At the last local election, smaller parties gained 13.1% of the vote in the Metropolitan boroughs; 9.2% of the unitary authority votes; 9.9% in London and 7.8% in the shires.