Georgian prosecutors have accused Patarkatsishvili of using his funds and his Imedi television company to attempt to organize a coup during mass street protests that shook the ex-Soviet republic last month.
The TV station was closed in November, but allowed to reopen on Thursday after opposition claims that they were being denied access to state media.
Patarkatsishvili has said that he sold his stake in the Imedi to Rupert Murdoch's News Corp. last year, but the Georgian authorities have refused to accept this.
Speaking on Friday after returning from London, David Usupashvili, one of the leaders of Georgia's Republican Party, told the TV station Rustavi 2 that the talks had seen a discussion of "common opposition plans and strategies".
Early presidential elections were announced in Georgia after demonstrators had taken to the streets from November 2-7 demanding the resignation of President Mikheil Saakashvili over corruption allegations. The protests were eventually put down by riot police, and Saakashvili subsequently announced early elections for January 5.
Conservative Party MP Kakha Kukava said that the opposition had agreed that all of their candidates, including Patarkatsishvili, who announced his candidacy in November, would "stand together until the end" to resist any attempts by Georgian authorities to falsify the results of the polls.
Zviad Dzidziguri of the Demfront fraction also commented in London that while Patarkatsishvili was currently "running and financing his own campaign at present," it was possible that any joint opposition campaign would be financed by the tycoon.
Patarkatsishvili has pledged to return to Georgia in the near future to run his election campaign.
