Under proposals accelerated by defence cuts, troops will return to the UK 15 years earlier than first planned

The UK military's long march out of Germany begins on Thursday when the Ministry of Defence announces details of a pullout that will eventually cover all 20,000 British troops there.

Under the plans, 1,800 will leave by next January, and then there will be a steady return home of another 8,200 by 2015. The rest will be back in the UK before the end of the decade – 15 years earlier than first proposed.

The pullout has been accelerated as part of the cuts announced in last year's Strategic Defence and Security Review, which was an attempt to streamline the armed forces at a time when billions were being taken out of the defence budget.

The British bases in Germany still represent the biggest deployment of UK forces overseas. With civilians, families and children, the British contingent in the country stands at more than 43,000.

The plans are likely to provoke fresh concern – here and in Germany – about the consequences.

A Whitehall source said: "This is the start of a process that will lead to all British troops leaving Germany by 2020. It is the end of an era that began at the end of second world war and lasted through the cold war."

Professor Malcolm Chalmers, of the Royal United Services Institute thinktank, said: "It has been 30 years since the end of the cold war, and it is arguable that there has been no real role for our forces in Germany since then, although there was uncertainty about what would happen in the years thereafter. This is symbolic. We will be returning to a time when all our armed forces are based in the UK. It may make us appear rather separate from our European allies. That is something we need to look out for."

As part of a major strategic announcement, the MoD will also announce what will happen to the main UK bases in Germany. The Trenchard Barracks in Celle and Münster station will be handed back to the German authorities, and Rheindahlen Military Complex will be closed. Some army units in Cyprus will also be brought back to the UK. The Waterbeach Barracks in Cambridgeshire will be sold.

A restructuring of the hierarchy of the army's regional brigades and divisions will also be outlined, including the closure of regional headquarters in Edinburgh, Shrewsbury and Aldershot – to be replaced by a new HQ in Aldershot, which will be operational by January next year. It will mean civilian and military job losses, but defence officials say this will also save £19m from the budget.

Chalmers said that the pullout in Germany might not have been possible without the decision by Liam Fox, the former defence secretary, to further reduce the overall size of the army to 82,000 from more than 100,000.

"The MoD didn't have the money to bring them back and find places for them to go to. But now that army numbers have been cut further, they will be able to relocate people from Germany at a time when overall numbers are being cut. We weren't able to do this before because of the extra capital costs, but that has changed."

While the case for keeping the bases in Germany was receding all the time, Chalmers said that the pullout would put extra pressure on military families.

Two former RAF bases have been refurbished for the regiments returning to the UK: RAF Cottesmore in Rutland, and RAF Kinloss on the Moray Firth.

In the first tranche of the pullout, the 620 strong 2nd Battalion the Royal Anglian Regiment will go to Cottesmore next year, where they will be joined by 7 Regiment the Royal Logistic Corps, which is currently based in Bielefeld, in north-west Germany.

The withdrawal of British forces has disappointed locals in North Rhine-Westphalia and Lower Saxony, where British forces are said to contribute an estimated €1.3bn (£1.1bn) to the economy.

Earlier this year, Rainer Prokop, the mayor of Bergen, a town near the Bergen-Hohne training area, told The Local website: "This is the most severe upheaval for us since the second world war. The British live among us, they are a part of everything here."

He also estimated the town's population would drop by a third once the UK troops left and that between 20% and 40% of local business could go bust.

MoD to announce withdrawal of the following units

43 Close Support Squadron RLC will move from Gütersloh, Germany, to Abingdon, Oxfordshire to collocate with its parent Regiment (12 Logistic Support Regiment) by the end of January 2012.

7 Regiment Royal Logistic Corps (RLC) will move from Bielefeld in Germany to RAF Cottesmore by summer 2013.

2nd Battalion The Royal Anglian Regiment (2 R ANGLIAN) to move from Cyprus to RAF Cottesmore in Rutland in July 2012.

2nd Battalion The Yorkshire Regiment (2 YORKS) to move from Cyprus to Elizabeth Barracks, Pirbright in July 2013.

39 Engineer Regiment (Air Support) will move from Waterbeach near Cambridge to Kinloss in the summer of 2012,

HQ 12 (Air Support) Engineer Group will move from Waterbeach to RAF Wittering in the summer of 2013.