The Crossrail 2 project will have significant long-term benefits for London's economy.
According to the Greater London Authority (GLA), the scheme is set to bring in £49 billion to the capital, while also tackling the chronic overcrowding problem.
With London's population set to reach ten million by 2031, measures need to be put in place to deal with this situation.
Transport minister Norman Baker recently called on the rail industry to do more to tackle the issue of overcrowding after statistics showed nine services in London had a load factor of over 150 per cent.
Valerie Shawcross, chair of the GLA's transport committee, said: "London needs a transport network that can cope with the millions of extra passengers that will travel on our tube and trains in future."
She described the investment in Crossrail 2 as cost-effective and thinks the project should be the "catalyst" to deliver London's Olympics regeneration dream.