Labour Leader Richard Leonard has pledged to call out the “tax and wage cheat” culture of some multinational giants.
He launched the party's Fair Tax Programme to make the City, big business and "tax dodgers" pay more of a fair share.
Mr Leonard claimed that current shortfalls in UK laws allow big firms to "rip off" the taxpayer and workers" as he campaigned outside Amazon's plant in Greenock.
But the firm rejected the claims and insisted it is "proud" of its investment in the UK.
"For too long those corporations with the broadest shoulders and the deepest pockets have been allowed to exploit the taxpayer and their workers," Mr Leonard said.
"They use loopholes to avoid paying their fair share of taxes while paying their workers poverty wages and at the same time companies like Amazon have been drawing on public money and claiming Regional Selective Assistance awards.
"In the past decade, inequality in this country has rocketed. The rich are getting richer while the poor are getting poorer and Labour will not stand by and allow it to continue.
"Under the Tory Government at Westminster, multinational corporations have been given tax cuts while ordinary working people have seen regressive taxes like VAT go up.
"The next Labour Government will tackle tax avoidance head on and fundamentally redistribute wealth and power in the interests of the many, not the few."
Labour will act against tax dodging by introducing unitary taxation of multinationals to stop tax avoiding profit shifting, which the party claims will bring in £6.3 billion in 2023-24.
It will also introduce a package of further measures through a Fair Tax Programme to raise £6.2 billion for the public purse in 2023/24.
The party has also pledged to clamp down on "tax dodging" through a series of measures, including increasing HMRC’s targeted audits, establishing an inquiry into the finance sector and introducing a 20% Offshore Company Property Levy.
But Amazon has rejected Mr Leonard's criticism.
A spokesman said: “These claims about Amazon are false. The Government wrote the tax laws and they are designed to encourage investment, and we are investing heavily in creating jobs and infrastructure across the UK - more than £18bn since 2010.
“This investment helped contribute to a total tax contribution of £793m during 2018 – £220m in direct taxes and £573m in indirect taxes. This year we announced plans to create 2,000 new jobs in the UK, taking our total workforce to over 29,500. Our associates receive industry-leading pay, with all employees earning at least £9.50 to £10.50 an hour depending on location.”