Wellington, Feb 9 NZPA - Going without coffee appears to be the first big test for Social Development Minister Paula Bennett as she begins her self-imposed famine to raise money for Haiti quake victims.

Ms Bennett today began a 40-hour fast to help boost World Vision's Haiti Appeal and has to get through Parliament's first sitting day for the year.

"I am definitely missing caffeine," she said this morning. "(National MP) Steven Joyce tried to talk to me about something and I said `not today mate, not a good day to take me on on that'."

The famine, which can be supported by sponsors, goes until 11am tomorrow and Ms Bennett said today's afternoon session in Parliament would be the most difficult part.

The famine.org.nz website said this morning the minister's efforts had almost raised $10,000.