The government and Auckland Council have established a hardship fund for businesses in Auckland's Albert Street.
Busineses along the city throroughfare have been plauged by disruption due to delays in the City Rail Link project.
Transport Minister Phil Twyford said the government had approved in principle a capped hardship fund for affected businesses who met certain eligibilty criteria.
"Hardship grants will only be paid to businesses negatively affected by the delay in construction and the businesses will need to open their books to demonstrate they were commercially viable before the works started."
Mr Twyford said he had also asked the Ministry of Transport to investigate options for business support for other public transport projects.
Auckland Mayor Phil Goff said he was pleased the government had agreed on the council's proposal to help those facing exceptional hardship.
"For those small business owners and their families this will be an enormous relief. The fund will be administered by CRLL and funded out of its existing contingency, so no extra funding is required."
Mr Goff said the fund was being established to recognise the difficult some of faced in light of the major transport project.
CRL chief executive Sean Sweeney acknowledged that the project had been disruptive for businesses at the lower end of Albert Street for much longer than expected.
"Supporting small businesses has been a project priority for some time and additional hardship assistance on top of the initiatives we have in place already should further help those who may qualify," he said.
The fund will be managed by CRL Limited and the budget will come from existing project costs.
But Dr Sweeney said there was extensive work to be done before the fund can be implemented.
"Our scope includes the size of the fund, how and who will manage the fund, and who will qualify for support.
"Our actions are directed at small businesses able to prove financial hardship caused by project delays. Long term, CRL will increase business opportunities along its alignment and the fund will not compensate for any inconvenience caused by construction.
"We also have a responsibility on behalf of New Zealand taxpayers and Auckland ratepayers to be prudent with our spending, and to operate a fund that is transparent and fair to all."
Businesses will need to open their books to prove they were commercially viable before construction started to access the grants.