A coronavirus community recovery fund worth £250m should be set up to support the hardest-hit communities, the Welsh Conservatives have said.
The party's group leader in the Welsh Parliament said it would help address a "public economic crisis".
Paul Davies said business rates could be scrapped for certain businesses in the worst-affected towns.
He said the money was already available, but Welsh Labour has questioned the figures.
The Conservatives' policy announcement follows the publication of a report that claimed a number of Welsh towns were among the most vulnerable across the UK.
Under the party's plans, a £250m fund would be established for the term of the next Welsh Parliament to support the worst-affected communities.
The Conservatives said it would allow the establishment of "business rate-free zones" where business rates would be scrapped for all businesses for three years.
Beyond those zones, the party wants to scrap business rates for businesses with a rateable value of up to £15,000.
Currently, businesses with a rateable value of less than £6,000 are exempt from paying rates and the amount payable is tapered for those valued between £6,000 and £12,000.
"We are going through not only a public health crisis, but we're also going through a public economic crisis," Mr Davies told the BBC's Politics Wales.
"And that's why it's absolutely crucial now as we come out of this pandemic that we support the communities which will be hardest-hit by this pandemic."
Mr Davies said the business rates relief scheme would "support those existing businesses in those communities, but also attract new businesses".
He claimed there was enough money in the Welsh Government's coffers to pay for the scheme as a result of UK government spending on the pandemic in England.
But a Welsh Labour spokesman said that was not the case: "The Welsh Conservatives seem not to understand that there are strict limits in the extent to which we can carry forward funds from one year to the next, with our maximum reserve being £350m.
"Small businesses with premises with a rateable value of less than £12,000 already get small business rate relief.
"While extending this further would be desirable, we would only be able to consider doing so if the Conservative government at Westminster were to provide a significantly more generous financial settlement."
Plaid Cymru's recovery plan includes guaranteeing a job for every unemployed 18-24 year old in Wales and setting up a "renewal fund" to "transform sectors identified as being hit hardest by Covid-19".