British Labour Party Ed Miliband on Sunday rejected as a “back of the envelop, fag packet” calculation Prime Minister David Cameron’s proposal to link further devolution to Scotland to a ban on Scottish lawmakers voting on English affairs.

“We have spent two years trying to keep our country together,” Miliband told the BBC’s Andrew Marr three days after Scottish voters rejected independence from the United Kingdom in a referendum. “Let’s not drive our country apart because David Cameron thinks it is an opportunity for him to do it.”

Cameron, who leads Britain’s ruling Conservative Party, said on Friday, “It is absolutely right that a new and fair settlement for Scotland should be accompanied by a new and fair settlement that applies to all parts of the United Kingdom.”

The following day, he warned that if Labour blocked such a proposal, Miliband would have to “explain to the people of the rest of the United Kingdom why they shouldn’t have the same powers as we are rightly devolving to the people of Scotland.”

There could be political benefit for Cameron in giving more autonomy to England — by far the largest part of the United Kingdom with 80 percent of its population and two-thirds of its economy. The Conservatives are more popular in England than they are in Northern Ireland, Scotland and Wales.

Miliband, by contrast, would struggle to govern nationally without the support of his 41 Scottish lawmakers. Opinion polls for next year’s general election put him only slightly ahead of the Conservatives.

The promise of more autonomy for Scotland, however — a promise Miliband supported before Thursday’s referendum — has highlighted the odd situation in which Scottish lawmakers in Westminster vote on legislation that affects other parts of the United Kingdom while English lawmakers have no say over Scottish affairs such as education and health care. If the Scottish Parliament in Edinburgh were also given power over pensions and welfare, the Conservatives say the English, Northern Irish and Welsh should be given similar control over their regional policies.

In the BBC interview, Miliband agreed more power should be devolved to England but refused to give specifics or endorse Cameron’s linkage of the issue to more autonomy for Scotland.