Germany is planning tougher rules for online shopping platforms to help combat sales tax fraud that is estimated to cost the country hundreds of millions of euros in lost revenue, a finance ministry spokeswoman said on Monday.

The draft law, reviewed by Reuters, would oblige operators of electronic marketplaces to record transactions that could be taxable in Germany. It will be discussed at Wednesday's cabinet meeting, the spokeswoman said.

It would make companies such as Amazon or eBay liable for any German taxes unpaid by users of their platforms, especially in cases where sellers who are unregistered for tax purposes sell their goods to German customers.

"It is clear that there is a need to act," the spokeswoman said. "We estimate conservatively that fraud is costing tax revenues in the three digit millions."