Ian Paisley's 30-day suspension from the House of Commons begins on Tuesday as Parliament returns from its summer break.
MPs voted to suspend him for failing to declare two holidays paid for by the Sri Lankan government and lobbying on its behalf.
He has also been suspended by the DUP.
A recall petition is open in his North Antrim constituency and will lead to a by-election if signed by 10% of constituents.
The petition is due to close on 19 September, but Tuesday 4 September is the last day for anyone wanting to sign the petition by post or by proxy.
Forms must be completed and delivered to the Electoral Office by 17:00 GMT.
Mr Paisley has said he would stand in any by-election in the event that one takes place, but has denied he might resign in an attempt to speed the process up.
After a parliamentary watchdog recommended he be suspended for 30 days, Mr Paisley apologised in the Commons, admitting "deep personal embarrassment", saying he had made a "genuine mistake".
Asked why he accepted the holidays, he said: "I would ask people to carefully consider my very genuine and my heartfelt comments.
"I've made my statement fully to the House. I believe it's up to other people to consider now what happens next."
Mr Paisley failed to declare two luxury family holidays in 2013 paid for by the Sri Lankan government.
He later lobbied the prime minister on the country's behalf.
A Westminster standards committee found he had breached the rule against paid advocacy by failing to declare his trips.
It also concluded the cost of the holidays was "much higher" than the £50,000 he had estimated.
Mr Paisley's suspension from the Commons is one of the longest ever handed down at Westminster.
On 13 August he apologised to some DUP supporters at a meeting in North Antrim.