The leader of the Welsh Liberal Democrats has called for the prime minister to ensure a no-deal Brexit is off the table before her colleagues back his demand for a 12 December vote.
Jane Dodds' party is calling for a general election three days earlier.
Boris Johnson is to press MPs again for a snap poll after they rejected his plan on Monday night.
Ms Dodds denied opposition splits after Plaid Cymru said a Brexit extension should be used for an EU referendum.
The bulk of Wales' MPs either voted against or abstained in a vote on whether the UK should hold a fresh general election.
Mr Johnson's motion failed to pass because it did not win the two-thirds majority needed. Of Wales' 40 MPs, only the six Welsh Tories supported the prime minister.
It comes after the EU's remaining states agreed to delay Brexit until 31 January, unless a deal is passed by MPs earlier than that.
Welsh Conservative assembly leader Paul Davies tweeted: "The public want Brexit delivered and for us as a country to move on. The only way it can be delivered is by holding a general election and voting Conservative."
On Monday night the prime minister announced his government would seek a different avenue for bringing about an election, which would require a simple majority by passing a bill.
It comes after the Lib Dems and the SNP proposed a similar plan, but with an election on 9 December instead.
While Brexit has been extended beyond 31 October, under UK law Britain will still leave the EU next year and would leave without a deal unless an agreement is passed before then, or the process is halted.
Ms Dodds said the Lib Dems needed to see the detail before they agreed to the UK government plan.
"But what we're clear about is that any bill presented by Johnson or anybody has to have no-deal Brexit taken off the table," she said.
"We perhaps don't trust him, but we need to make absolutely sure that a no-deal Brexit is off the table. And that's what we're looking for."
Explaining why the Lib Dems were calling for an election on 9 December, she added: "We know that having it slightly earlier would mean the opportunity for students to vote. After all, it is their future."
David Davies, Conservative MP for Monmouth, said he had no problem with the election being held on a different date to 12 December.
"I don't really understand why frankly, I don't really care which day it's on. It needs to be done - we need an election" he said.
"If the Liberals want it three days earlier or three days later, I can't fathom why that should be, but fine, give it to them. I don't really care.
"I'm perfectly flexible on it myself and I'm sure the government are."
Plaid Cymru's Westminster leader Liz Saville Roberts said a general election "does not solve the Brexit crisis".
She called on her Commons colleagues that back a "People's Vote" - a further referendum on the UK's status in the European Union - to "now stand up and be counted".
"Today, reality collided with his fantasy Brexit and he was forced to accept an extension to the process," she said. "If the prime minister is so confident in Brexit, surely he doesn't fear putting it to the people?"
Most Labour MPs stayed away from the vote on Monday night - effectively abstaining.
Ms Dodds and Plaid's four MPs voted against the government motion.
They were joined by Labour MPs Tonia Antoniazzi, Ann Clwyd, Anna McMorrin, Albert Owen, Owen Smith and Jo Stevens.