The TA will be renamed the Army Reserve in a bid to bolster the regular forces, with more days' training – from 35 to 40 a year – an increase in numbers to around 35,000 across all three services by 2020, and an extra £1.8 billion during the next decade for new equipment, uniforms and training.
"The changes I'm proposing amount to a paradigm shift in the role of reservists in delivery of the nation's security," declared Philip Hammond, the Defence Secretary, in a speech in London, which launched a consultation exercise on the Government plans.
"To achieve this shift, wider society will need to play a wider part in the delivery of national security. Our national security is everyone's business," he said.
The Army will see the biggest change with 30,000 trained reservists, creating a total land force of around 120,000 – 20,000 soldiers from the regular Army are being cut by 2020.
There are around 3500 Army reservists in Scotland covering not only infantry battalions but also medical, engineering, artillery and logistics units.
Mr Hammond said: "Reserve units will be paired with, train with and achieve the same standards as their regular counterparts. They will use the same equipment, the same vehicles and wear the same uniforms as regulars, and they will deploy routinely, together with regular forces on overseas exercises."
He stressed the UK Government consultation was about working with reservists, their families and employers to use the extra resources to "design the reserve forces of the future".
John Cridland, the CBI chief, welcomed the planned shake-up but made clear there would have to be detailed discussions with the business community.
He said: "Employers are up for this. But the only way we're going to get this right is if there is a real partnership, where the business side is critically part of the coalition of the willing of making this work.
Mr Hammond also announced more reservists from the reformed armed forces would be stationed on the Falkland Islands.
However, Tory backbencher Patrick Mercer, a former Army officer, insisted the Falklands should be defended by regular forces, noting: "Anything else sends the wrong message to the Argentinian aggressor."
In the Commons, Jim Murphy, the Shadow Defence Secretary, backed the proposed TA name change and a suggested kitemark for employers who supported reservists. But he attacked the decision to cut regular Army numbers before new volunteers were recruited and trained.
He called for more post-tour care for reservists as well as new laws to safeguard volunteer service personnel against being overlooked for promotion or pay rises because of their roles in the reserves.