After the success of his vow proposal in 2014, former British prime minister Gordon Brown is rehashing the idea of an alternative "third option" for Scotland, as the country gears up for another independence referendum.

The proposal, in which Brown promised more powers to Holyrood if the Scottish voters voted 'No' in the first referendum in 2014, has taken on a new life as Brown has reshaped it to leverage more powers for Holyrood after Brexit.

In a bid to draw a line between "die-hard conservatism" and "hard line nationalism", Brown's agreement would give Scotland the freedom to set VAT rates, sign international treaties and take power over agricultural, environmental and fishing agreements.

Addressing Scotland's annual Festival of Ideas in Fife, Brown will roll out the new federal home rule and will call for £800m ($991.9m) currently paid to the European Union to be repatriated to Scotland after Brexit.

He is expected to say: "The third option, a patriotic Scottish way and free from the absolutism of the SNP and the do-nothing-ism of the Tories, is now essential because post-Brexit realities make the status quo redundant and require us to break with the past.

"The status quo has been overtaken by events because unless powers now with the European Union are repatriated from Brussels to the Scottish Parliament, the Welsh Assembly and the regions, Whitehall will have perpetrated one of the biggest power grabs by further centralising power, employment and energy.

"The patriotic way means that Scotland is not caught between a die-hard conservatism that denies the Scottish Parliament the powers it needs and a hard-line nationalism that throws away the resources we secure from being part of the Union."

Working alongside Scottish Labour leader Kezia Dugdale, the former prime minister hopes to campaign for a People's Constitutional Convention to look at how power is distributed across the nations and regions of the UK.

It appears that both the left and right factions of English government are against the call for a new independence referendum.

"The tunnel vision that SNP has shown today is deeply regrettable," said Prime Minister Theresa May. "Instead of playing politics with the future of our country, the Scottish government should focus on delivering good government and public services for the people of Scotland. Politics is not a game."

After telling the Press Association that he was "absolutely fine" with a new Scottish independence referendum, Labour leader Jeremy Corbyn said since said his party was "not in favour of a referendum".