The party’s So Yat-hang was among seven Hong Kong Island district councillors unseated after authorities decided their pledge of allegiance was invalid.
Lo said on an RTHK programme that he believes So was ousted because of his involvement in the Legco primaries held in July last year, but emphasised that it was just his guess.
“The red line may be like this today, but tomorrow will there be a new line? Will it include something else or exclude some other things? Nothing can be clearly defined,” he said.
He said the public would have expected the government to state clearly what kind of conducts would be deemed as a violation of the oath.
The Hong Kong Island councillors are the first the take the oath of office, but Lo said the party’s district councillors from other constituencies have yet to inform him whether they would take the oath.