GORDON Brown will today enter the EU referendum debate with a powerful plea for Britain to remain part of the 28-state bloc to maintain its economic prospects, security and influence in the world.

The former Labour Prime Minister will use a speech in Edinburgh to say Scotland could vote by an overwhelming 70-30 majority in favour of staying in the EU if supporters make a strong case based on the "needs and aspirations" of ordinary families.

He will reject claims that leaving the EU would make the country less vulnerable to terrorist attacks, and warn it would amount to a "betrayal of our history" to abandon fellow member states facing the same threats.

Mr Brown, who stepped down as an MP at the last election, will also argue that quitting the EU would still require Britain to follow EU rules and regulations without an opportunity to shape them.

David Cameron is continuing his efforts to renegotiate Britain's terms of membership with a visit to Germany.

The Prime Minister hopes to secure a deal next month, leading to speculation a vote could be held as early as June or July.

Nicola Sturgeon, the First Minister, is set to lead an In campaign on behalf of the SNP.

She has warned that Britain's exit from the EU, if a majority of Scots vote to remain, could trigger a second independence referendum.

Mr Brown will make the "In" case as he helps launch a new campaign spearheaded by the Scottish Labour Movement for Europe.

The group, chaired by Labour peer and former MSP George Foulkes, will work alongside the Labour In For Britain campaign, headed by former cabinet minister Alan Johnson, organisers said.

Mr Brown will cite a plethora of figures showing 300,000 jobs in Scotland are linked to the EU and highlighting the importance of Europe for inward investment and exports.

He is expected to say: "We must start this debate from the needs and aspirations of Britain's working families - not institutions and constitutions - and make the case for exactly what kind of country we want to be.

"This referendum should be about jobs, security and the future prospects of our young."

In the only previous referendum on the EU, in 1975, 68 per cent of voters backed Britain's membership, though the figure was 58 per cent in Scotland.

However, in recent years support for the EU has been stronger in Scotland.

Last November, it reached its highest level yet when 65 per cent of Scots said they wanted to remain in the EU, compared with 22 per cent who wanted to leave and 13 per cent who were unsure, according to an Ipsos MORI poll for STV.

A month earlier, the same pollster put support for the EU at 52 per cent among English voters, with 36 per cent wanting to leave and 12 per cent undecided.

Mr Brown will say Scotland can do "much better" than in 1975 and add: "If we put forward a positive, principled and progressive case, we can win 70 per cent for versus 30 against."

In an echo of his frequent interventions in the independence debate, Mr Brown will warn against "isolating ourselves or going it alone" and stress the need for strong relationships with neighbours.

He will also argue the need for "British values" of tolerance, liberty, fairness and social responsibility to shape Europe.

"Our destiny can never be to be some kind of bit-part player semi-detached on someone else’s stage or a bystander hectoring from the wings," he will say.

Writing in the German press today, Mr Cameron, who has travelled to Bavaria to attend the party conference of the state’s ruling right-wing CSU party, argues his proposed changes to EU rules, including curbing welfare payments to migrants, will benefit the whole bloc.

The Labour Leave campaign, led by ex-MP Nigel Griffiths, will launch a poster campaign in Edinburgh today highlighting the £19billion annual cost to Britain of its EU membership.