Mr Hammond delivered the message to Ministers during a three-hour Cabinet meeting on Tuesday.
He claimed the UK would still have to pay all but £3-9billion of the agreed £39billion divorce payment should Britain leave the EU without agreeing a future trading relationship.
A Minister told The Daily Telegraph: “He said that the Treasury’s legal advice was that if we left without a deal we would still have to pay the EU £30-36billion because we would be unlikely to win any case that went to international arbitration.”
The advice directly contradicts Brexit Secretary Dominic Raab who claimed in July that the £39billion payment would only be made if a future trading deal was agreed with the EU.
He insisted the money would not be handed over unless the EU fulfils “its side of the bargain”.
A Treasury spokesman claimed the Chancellor’s view “remains that of the Prime Minister, this is that we are a country that honours our obligations”.
In December the Government agreed to pay the EU a divorce settlement to cover the UK’s debts and liabilities, estimated at around £39billion.
The figure includes continuing UK contributions to the EU budget for 2019 and 2020 and Britain’s share of the EU’s unpaid bills, mostly from projects Brussels has agreed to fund but not yet paid for.
Mr Hammond’s warning provoked a powerful response from Brexiteers.
Jacob Rees-Mogg, chair of the European Research Group which campaigns for a clean Brexit, said: “It’s simply wrong.
“The House of Lords produced an authoritative report which set out that we have no obligations under UK, EU or international law to pay anything if we leave under the terms of Article 50 without a withdrawal agreement.
“It’s a cavalier approach to taxpayers’ money.
“I didn’t realise the ending of austerity meant drowning the European Union in cash.”
However, an ally of Mr Hammond claimed: “This is not Philip being a Remoaner.
“He is growing increasingly frustrated with the EU’s tactics, and although he won’t say it publicly his stance on how much we should pay them is hardening.”
Should the UK refuse to pay the exit bill, the EU could take legal action via the International Court of Justice or Permanent Court of Arbitration.