This Jan 31, 2020 photo shows the British Union Jack waving in front of the European Parliament in Brussels on the Brexit day. (KENZO TRIBOUILLARD / AFP)

Some European Union member states have warned the bloc not to allow the United Kingdom to leave without a trade deal because the financial hit would be too much following the economic cost of the novel coronavirus pandemic.

The UK officially left the EU on Jan 31 but remains bound by its laws until the end of 2020 while talks continue for a replacement trade deal

The nations, said to include Belgium and Ireland, reportedly believe a hard Brexit would be catastrophic while the bloc is facing its most serious postwar economic slump to date.

The Financial Times said diplomats made the suggestion during recent talks related to the bloc's seven-year budget and the US$852-billion recovery fund that will support EU members－including France, Italy, Poland, and Spain－as they emerge from the outbreak.

The UK officially left the EU on Jan 31 but remains bound by its laws until the end of 2020 while talks continue for a replacement trade deal.

But those negotiations have been difficult and, if the parties fail to reach an agreement, the UK could leave without a deal and resort to trading under World Trade Organization rules. Experts say such an arrangement, a so-called no-deal or hard Brexit, would slow the flow of goods and services and add to their cost.

With the EU's economy predicted to shrink by 8.7 percent this year due to the virus, the EU member nations say the bloc must avoid additional costs.

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They have also reportedly noted that the EU's novel coronavirus fund will offset some of the cost of the virus fight for some nations, but that there is not a similar fund to support nations that would be hit hard by a no-deal Brexit.

The Express newspaper claims the warnings will further complicate trade deal negotiations.

An EU official told the newspaper: "We are consistently trying to remind member states, but also all stakeholders, that under all circumstances－deal or no deal－at the end of the year the commercial relationship between the EU and UK will look very different."

Reuters reported that the EU is also prioritizing a deepening of the bloc's capital market, as a way to recover from the impact of the virus.

It said the move would reduce the bloc's reliance on the City of London financial district for currency transactions.

An EU report released on Wednesday lamented that the bloc still relies on UK-based banks.