"The President had the option of dissolving parliament instead he sought public mandate to appoint me as the Prime Minister and have a 100-day government", Wickremesinghe said addressing a public rally at Galgamuva in north western province.
"I tell them to face elections, I am ready, our party is ready", he said.
The opposition led by United People's Freedom Alliance (UPFA) had moved a motion of no confidence against Wickremesinghe.
The no-confidence motion deals with several matters, including the controversial treasory bond issue, surrounding Wickremesinghe and accuses him and his United National Party (UNP) of political high-handedness.
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He has been accused of political high handedness while holding the position to which he had not got a public mandate.
"The only honourable option left for the Prime Minister is now to resign", Rajapaksa supporter and former minister Gamini Lokuge said.
GL Peiris, former external affairs minister asked Sirisena to sack Wickremesinghe and appoint a Sri Lanka Freedom Party (SLPF) member as PM as the party still commands majority in the House.
Rajapaksa loyalists in the Sri Lanka Freedom Party now led by Sirisena demand that Wickremesinghe be sacked and replaced by a Rajapaksa loyalist.