Theresa Makone is from the MDC, which joined President Robert Mugabe and his Zanu-PF party in a unity government in 2009 after years in opposition.
She said that Zanu-PF wants to stop her and other MDC MPs voting in next week’s election for a speaker of parliament.
Tension is again rising in Zimbabwe ahead of possible elections this year.
Ms Makone said she had been told that another MP and Lovemore Moyo, the former speaker of parliament, also faced arrest.
Zimbabwe’s Energy Minister Elton Mangoma was earlier arrested for a second time this month.
The 2008 election of Mr Moyo as speaker of parliament was nullified by the Supreme Court two weeks ago, following a complaint by a Zanu-PF official, who said the vote was “disorderly”.
Meanwhile Ms Makone accuses Zanu-PF and their allies in the security forces of trying to prevent MDC MPs from voting, to ensure their candidate wins the new election.