Northern Powerhouse Rail has often been referred to in the press as "High Speed 3" or "HS3", in reference to the development of high-speed rail in the United Kingdom.
The first high-speed railway line to be built in Britain was High Speed 1 (HS1), the route connecting London to the Channel Tunnel, which opened 2003–2007.
The southern phase of a second high-speed line named High Speed 2 (HS2), which is planned to eventually run from London to Manchester and Leeds, is currently being constructed and is estimated to come into service in 2026.
The HS3 designation implies the development of a third  high-speed rail route.

Historically, the use of the term High Speed 3 has been loose – the House of Lords' Economic Affairs Committee (March 2015) stated that there was no firm definition of the route implied by HS3:
Improvements to east-west links in the north of England have often been referred to as "HS3".
This term has been used interchangeably to mean the connection between Leeds and Manchester or a longer route running from Liverpool to Hull via Manchester and Leeds.
Such a railway would not necessarily need to be high-speed. [..]
We refer to "east-west links" rather than "HS3" in this report as there is no clear indication yet what form or route the proposals might take or if the trains will be "high speed" in the same sense as HS2.

— The Economics of High Speed 2, Economic Affairs Committee (2015).

In June 2014, at a speech given at the Manchester Museum of Science and Industry, the incumbent Chancellor of the Exchequer, George Osborne proposed a high speed rail link between Leeds and Manchester; the line would utilise the existing route between Leeds and Manchester, with additional tunnels and other infrastructure.
Osborne argued that the northern cities' influence was comparatively less than London's and that the link would promote economies of agglomeration.

Osborne suggested the line should be considered as part of a review of the second phase of High Speed 2.
Initial estimates suggested a rail line with a 140 miles per hour (230 km/h) line speed, and Leeds-Manchester journey times reduced to 30 minutes.
Osborne estimated the cost to be less per mile than that of HS2, giving a cost of under £6 billion.
Initial responses to the proposal were mixed: Jeremy Acklam of the Institution of Engineering and Technology (IET) suggested that planners should look at connecting other northern cities such as Liverpool, and potentially North East England via York; commentators noted that the proposal could be viewed as an attempt to gain political support in the north of England in the run-up to the 2015 general election: the Institute of Economic Affairs characterised the proposal as a "headline grabbing vanity project designed to attract votes".
The British Chambers of Commerce, Confederation of British Industry and others were cautiously positive about the proposal, but emphasised the need to deliver on existing smaller scale schemes.
Northern Powerhouse Rail has often been referred to in the press as "High Speed 3" or "HS3", in reference to the development of high-speed rail in the United Kingdom. The first high-speed railway line to be built in Britain was High Speed 1 (HS1), the route connecting London to the Channel Tunnel, which opened 2003–2007. The southern phase of a second high-speed line named High Speed 2 (HS2), which is planned to eventually run from London to Manchester and Leeds, is currently being constructed and is estimated to come into service in 2026. The HS3 designation implies the development of a third  high-speed rail route.
Historically, the use of the term High Speed 3 has been loose – the House of Lords' Economic Affairs Committee (March 2015) stated that there was no firm definition of the route implied by HS3:
Improvements to east-west links in the north of England have often been referred to as "HS3". This term has been used interchangeably to mean the connection between Leeds and Manchester or a longer route running from Liverpool to Hull via Manchester and Leeds. Such a railway would not necessarily need to be high-speed. [..] We refer to "east-west links" rather than "HS3" in this report as there is no clear indication yet what form or route the proposals might take or if the trains will be "high speed" in the same sense as HS2.
— The Economics of High Speed 2, Economic Affairs Committee (2015).
In June 2014, at a speech given at the Manchester Museum of Science and Industry, the incumbent Chancellor of the Exchequer, George Osborne proposed a high speed rail link between Leeds and Manchester; the line would utilise the existing route between Leeds and Manchester, with additional tunnels and other infrastructure. Osborne argued that the northern cities' influence was comparatively less than London's and that the link would promote economies of agglomeration.
Osborne suggested the line should be considered as part of a review of the second phase of High Speed 2. Initial estimates suggested a rail line with a 140 miles per hour (230 km/h) line speed, and Leeds-Manchester journey times reduced to 30 minutes. Osborne estimated the cost to be less per mile than that of HS2, giving a cost of under £6 billion. Initial responses to the proposal were mixed: Jeremy Acklam of the Institution of Engineering and Technology (IET) suggested that planners should look at connecting other northern cities such as Liverpool, and potentially North East England via York; commentators noted that the proposal could be viewed as an attempt to gain political support in the north of England in the run-up to the 2015 general election: the Institute of Economic Affairs characterised the proposal as a "headline grabbing vanity project designed to attract votes". The British Chambers of Commerce, Confederation of British Industry and others were cautiously positive about the proposal, but emphasised the need to deliver on existing smaller scale schemes.
High Speed North