Labour assumes the support of smaller parties is "in their back pocket", Plaid Cymru's leader Leanne Wood has said.
Ms Wood claimed Ed Miliband has "arrogantly" pushed away her party's offer of support, adding she believed he should revise his position after polling day to prevent a Conservative government.
Ms Wood said the smaller parties will have a say, arguing it would be "anti-democratic" to ignore them.
Ed Miliband has said the Labour party will not negotiate with the SNP after the General Election.
Speaking on the Today programme, the Labour leader said: "Are we going not going to negotiate about our Queen's Speech, no. We are not going to negotiate with the SNP.
"I am going to put a Labour Queen's Speech before the House of Commons. I want to put a Labour budget before the House of Commons."
The Labour Party leader Ed Miliband has said voters face a "huge choice" when the country goes to the ballot box on Thursday.
He told the Today programme: "There is a huge choice between a country run by the richest and most powerful, if we have a continuation of a Conservative Government, or a Labour Government which will put working people first."
Yesterday's rain will become confined to the Northern Isles by midday, clearing Shetland late this afternoon.
Elsewhere it will be mainly dry with sunny spells developing, though some showers are likely towards western Scotland and Northern Ireland.
It will be markedly warmer across Scotland than yesterday, and will widely feel pleasant out in the spring sunshine.
Some rain is then set to spread into the far south/southwest later on.
Texas police shot dead two gunmen who opened fire outside an exhibit of caricatures of the prophet Muhammad being held at an indoor arena in the suburb of Garland, northeast of Dallas.
Police said they had not immediately determined the identity of the two gunmen or whether they were linked to critics of the event who had branded it anti-Islamic.
A security officer who was shot in the leg by the two attackers was treated at a local hospital and later released. No one else was injured.
Bomb squad experts are searching for explosives in the car of two gunmen who were shot dead after opening fire on a security officer outside a contest for cartoon depictions of the Prophet Muhammad.
Spokesman Joe Harn with the Garland Police Department said the bomb squad was searching the vehicle outside the Curtis Culwell Center as a "precaution."
He added that the bodies of the two gunmen, who are yet to be identified, have not yet been removed from the scene.
"Because of the situation of what was going on today and the history of what we’ve been told has happened at other events like this, we are considering their car possibly contains a bomb.”
The injuries suffered by the security guard during the Muhammad art event shooting in Garland are not life-threatening, the city authorities have confirmed.
The guard was shot when two men opened fire outside the Curtis Culwell Center where the event was coming to an end around 7pm. Police officers then shot both men dead.
Writing on its Facebook page, the City of Garland described how the shooting unfolded.