Speaking to the Daily Mirror, EC Chairman Mahinda Deshapriya said on Monday that his office mulled action against these candidates.
"The Commission noted seven candidates supporting one main candidate and six supporting the other," he said.
When asked how these candidates canvassed for the main contenders, he said their authorised agents were seen on the two candidates' stages.
Besides, Deshapriya said that the secretaries to political parties represented by these candidates addressed election rallies in support of either of the two main contestants.
"The increase in cash deposit required for contesting the election and denial of registration for parties doing so will serve as deterents," he said.
There are 35 contestants in the fray this time, which has resulted in an unnecessary workload for the commission, according to the EC Chair.
"Ballot paper will be too long this time. We need additional ballot boxes," he added.
Also on Monday, the EC announced that it would set up 45,000 polling booths across the country for the November 16 presidential election.
EC officials said that during previous elections, only 35,000 polling booths had been set up island-wide, but this year, 10,000 additional booths would be added due to the two-feet long ballot paper.
These are the island nation's eighth presidential election, with incumbent President Maithripala Sirisena's term coming to an end in January 2020.
( With inputs from IANS )