Wales Office Minister David Jones has said it would be "very tight" to get a referendum on extra assembly powers this autumn.
Speaking on the BBC Politics Show, the Clwyd West MP said that his department had made a referendum "an absolute priority".
But he said there was still much work to be done.
He said that the actual wording of the question had to be gone through properly.
After this, the Electoral Commission needed 10 weeks to "road test" the question.
On Friday, David Melding, the Conservatives' Welsh policy director told BBC Radio Wales's Called To Order programme that he would like to see a referendum this November.
The assembly member for South Wales Central said: "From the discussions I've been having from within the Conservative party and with other parties in the assembly, we all think that the best date, if possible, would be the autumn.
"But we need the green light from the Electoral Commission before we can road test the question but I myself think if that if all parties urge a November date then I think that might be the answer.
"We shouldn't argue about when we should have the referendum - what will the public think if we can't even agree amongst ourselves when the vote should be."
But Mr Jones told the Politics Show that after the 10 week "road test", another 10 weeks to six months could be required on the process.
"It is a major constitutional proposal. It's absolutely right that the question is right and the people of Wales are given enough information to make an informed judgement."
Mr Jones added that he and Welsh Secretary Cheryl Gillan, would remain neutral on the referendum.
"It's a quasi-judicial process and there will be a lot of people watching to see if the Wales Office makes any slip ups, so our position is that we stay absolutely neutral".
The Liberal Democrat AM, Mike German, told the Politics Show that he would be providing a "strong voice" for the Assembly and extra powers when he takes up his seat in the House of Lords later this year.
'Open and honest'
"Wales needs a strong voice both in Westminster and here in Wales," he said.
"If you are talking about fighting a campaign for a referendum on a yes vote for Wales, I can guarantee that I'll be very much at the heart working for that."
On the wider issue of the House of Lords, Mr German would like an elected upper chamber: "I have made no bones about it, my job is to abolish myself. That's the challenge.
"By the end of the five year cycle of this government in London, I hope to have abolished myself and in that way, the government will become much more open and honest with the people of Wales and the rest of the United Kingdom".