PROJECT Fear campaigns don't work and just make people more likely to vote in the opposite direction, Theresa May's former chief of staff has said. 

Fiona Hill said the former prime minister was concerned about being "forced" into scaremongering during the 2014 Scottish referendum.

Mrs May was Home Secretary between 2010 and 2016 under then prime minister David Cameron. 

The term "Project Fear" gained popularity during the independence referendum as a jibe against negative campaigning by the No side.

Ms Hill rubbished it as a tactic during a panel discussion at a conference held by the pro-Union These Islands thinktank in Newcastle on Friday.

She said: "My experience from the last referendum, the question is what language do we use. 

"I say that because, during that period, I was genuinely concerned, as my boss was, Theresa May, as was Alistair Darling, that we were forced into doing what people described as this Project Fear campaign and I just don’t think those campaigns actually work. 

"I think they make people more isolated and more likely to vote in the opposite direction."

Ms Hill, who is from Greenock, served as joint Downing Street chief of staff alongside Nick Timothy.

The pair resigned following the 2017 general election, in which the Tories lost their majority.

The political adviser was one of a number of speakers at the These Islands event, which saw representatives from every major pro-UK party appear together publicly for the first time since 2014.

Elsewhere, Scottish Liberal Democrat leader Willie Rennie dismissed any suggestion of a Unionist alliance to defeat the SNP at the Holyrood election next year. 

He told attendees: "I'm not talking about any pacts or anything like that. I'm not in support of that, because we are different parties."

Meanwhile, former prime minister Gordon Brown warned British politics is now split by five competing nationalisms – centred on Brexit, Scotland, Wales, Ireland and Ulster. 

He said these forces are driving today’s politics, and insisted the UK’s internal problems cannot be dealt with through “cosmetic measures” such as Boris Johnson’s plan for a bridge between Northern Ireland and Scotland.

Mr Brown also took a swipe at the “petty divisions” between UK and Scottish ministers over the COP26 climate change summit and drug deaths. 

He said: "You have got to find a way of showing you are able to cooperate. Look, drugs policy in Scotland – thousands of kids and adults dying. 

"Scottish and UK governments arguing over who does what, who is responsible and who is to blame. 

"They can’t even organise one seminar together they have got to organise two, one day after the other. 

"Why can’t they get together and work out a drugs policy?"