Tuilaepa and the HRPP's secretary Lealailepule Rimoni Aiafi were suspended indefinitely without pay on Tuesday from Parliament following a formal complaint by the Deputy Prime Minister, Tuala Iosefo Ponifasio.
The complaint led to a report with the recommendation they both be suspended.
Prime Minister Fiame Naomi Mata'afa told Parliament an indefinite term of suspension is appropriate to monitor Tuilaepa and Lealailepule's behaviour and set a precedent for future reference.
The pair have also been denied their usual privileges payments during their suspension.
Political journalist, Tuiasau Uelese Petaia, told Pacific Waves the suspension has the left Samoa's Opposition party in a tight spot.
"The decision means the Opposition will be without a leader, I don't know where that would lead the party, in terms of whether they will wait around and see how long the suspension is or whether they would decide to find a new leader.
"But those are some of the issues that will start to come to the fore in the next couple of weeks."
Ex-PM to take legal action
Tuilaepa said he and the HRPP would take legal action against the government over the suspensions.
In a letter to the Samoa Observer, Tuilaepa said the sole reason for the one-day session of Parliament on Tuesday was so he and Lealailepule could be suspended.
Tuilaepa wrote to the Speaker, Papali'i Li'o Ta'eu Masipa'u, pointing out the motion was illegal, and that it should be dismissed.
He said both of them are in Parliament's Public Accounts Committee and their suspension comes seven days before the tabling of the Faatuatua I le Atua Samoa ua Tasi (FAST) government's 2022/23 main budget.
"When this motion was first tabled in Parliament, both Hon Tuilaepa and Hon Lealailepule wrote to the Speaker Hon Papali'i Li'o Ta'eu Masipa'u pointing out the motion was illegal and he should therefore dismiss it," wrote Tuilaepa.
According to Tuilaepa, Standing Orders 185 of Parliament stipulates that a contempt action on a matter of privilege must be an action that clearly hinders Parliament, or an MP, from the performance of its or their duties.
"Therefore, the allegation has no legal basis under the Standing Orders," he wrote.