Thailand's Constitutional Court says it will accept a landmark case that could lead to the dissolution of both the ruling party and the main opposition.
Thaksin Shinawatra's Thai Rak Thai could be dissolved
The accusations follow a probe ordered by the attorney-general's office.
Both the governing Thai Rak Thai party and the opposition Democrats are accused of electoral fraud, relating to a controversial poll in April.
This is the latest twist in a saga which has kept Thailand's political system in limbo for months.
All the allegations against the two main parties refer to alleged violations during the run-up to the April election, which has since been annulled.
The Democrats face charges relating to their decision to boycott the poll, while Thai Rak Thai is accused of financing smaller parties in an effort to make the election appear more legitimate.
Three fringe parties will also face charges.
This trial could potentially leave Thailand without its two main political parties, although analysts say this is unlikely.
Since the election was annulled, the nation's courts have been under pressure to find a way out of the impasse, but with claims and counter-claims being filed in every direction, analysts say they are making little headway.
New elections are scheduled to go ahead in October, but in the light of the current mess even that seems far from certain.
Meanwhile Prime Minister Thaksin Shinawatra - the head of Thai Rak Thai and the man often seen as being at the centre of this political crisis - has confirmed that there have been intelligence reports of a plot to assassinate him.
But he downplayed the threat, telling Thai media there was "nothing to worry about".