Interim election

The chief of BNP very often demands interim election in Bangladesh. She knows it very well that her demand has no merit because the present government is in firm footing with 3/4th majority and no such interim election ever happened in the past in Bangladesh so the only way to remove this government is through “no-confidence” motion in the parliament. Why is she then talking about interim election in the country? How does she know that if there is an interim election the people will vote for her? Instead of demanding an interim election she should campaign for a free and fair election next time. Only free and fair election will bring permanent democracy in Bangladesh.