Marks and Spencer Group PLC believes a tax on online sales would damage the High Street, by leaving retailers with less money to invest in physical stores.
In a letter to Chancellor Rishi Sunak, seen by the BBC, the chain’s chief financial officer Eoin Tonge argued that a new tax would "punish" retailers.
The letter was written in response to a three-month government consultation on whether to introduce an online sales tax, which closes on Friday.
The Treasury has said it would spend the income from such a tax to reduce business rates for shops.
"Introducing an additional tax on retail - already overburdened - will simply mean retailers cut their cloth accordingly," Tonge said.
"This rationalisation will always start with the least profitable parts of a business - which, in the case of multi-channel retailers, will more often than not be High Street stores."
"Therefore it is likely that, far from helping the High Street an online sales tax will damage shops and our high streets further, particularly in areas that require new investment to bring them back to life."
The Treasury has not yet decided if it will introduce the tax, the BBC said.