An early July election is not probable, but it is possible, Deputy Prime Minister Barnaby Joyce says.

“I think that is one of the big mistakes … possibilities and probabilities are getting confused on this issue,” he told reporters in Sydney on Friday as he responded to speculation about government plans for a double dissolution election.

Australians would be going to the polls some time between July and October, Mr Joyce said.

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“We’re talking about a four-month period in a term of government that goes for three years. I don’t think this is quantum mechanics.”

If that meant going to an election at the first opportunity in July, “that is not a probability, that is a possibility”.

Earlier, cabinet colleague Christopher Pyne said July 2 was “as good a time” to go to the polls.

But he told the Nine Network: “I don’t think that there is any plan to have an election in July.”

The last time an election was held in July was 1987, he noted.

Independent senator Glenn Lazarus believes the government is moving towards an early poll because it’s unhappy a lot of its “rubbish” legislation isn’t getting through parliament’s upper house.

The fact the government was “ramming through” Senate voting changes was very telling, he told ABC radio.

The deadline for a double-dissolution election to be called is May 11, the day after the federal budget is handed down.