Home Secretary Theresa May is said to be in favour of their deployment by police for the first time outside of Northern Ireland amid fears of summer riots.
Both the Metropolitan Police and the Association of Chief Police Officers (Acpo) have requested them to tackle any civil unrest caused by welfare cuts and June's G8 meeting of world leaders.
Talks are at such an advanced stage that the type of cannon they want to use has even been identified.
The intimidating Ziegler Wasserwerfer 9000 is capable of carrying up to 9,000 litres of water, or even tear gas, which can be fired at rioters at the powerful rate of 1,100 litres per second.
The jet is mounted on a heavy-duty vehicle weighing 29 tonnes that is also equipped with CCTV cameras and searchlights at both the front and rear.
They are understood to cost about £1.3million each, with an order for three being considered.
The Met believes they would be a "valuable option in rare situations" and it has worked with Acpo to develop a formal business case detailing the operational, technical and medical implications of using them.
It is understood that an initial Home Office licence would cover the use of basic water only.
A Home Office source told the Sunday Express: "There's an urgency to get the water cannons by the summer.
"Theresa May is actually pushing for it. The G8 is a worry for them."
An official Home Office spokesman said: "We will ensure forces have the tools and powers they need to maintain order on our streets.
However, MP Keith Vaz said: "We need to tread very carefully over the use of water cannons which I know are favoured in continental Europe.
"After the riots two years ago, we received very little support for the development of water cannons.
"There needs to be full consultation on this issue."