The government is expected to open a £10m Brexit fund for English ports but, with grants limited to £1m per marine gateway, industry figures dismissed the proposal as “a tiny amount of money”.

The infrastructure resilience call for English ports is expected to be announced by the Department for Transport this week.

The British Ports Association said: “At this late stage a deal was the best way to avoid potential disruptions at the border” and grants of £1m would not achieve anything significant in terms of Brexit preparedness in the event of no deal.

“Some people say this is too little, too late. It is a tiny amount of money. It is not going to redesign a terminal for Brexit,” said the BPA chief executive, Richard Ballantyne.

“But equally there is not a long way to go before 31 October so there isn’t much time to apply and spend money,” he added.

“A no deal would certainly appear to be more of a possibility now and it is prudent to plan for this potential outcome.

“However, we remain firmly of the view that a deal that supports frictionless, free-flowing frontiers is the best outcome and as far as we are aware this is still the government’s aim,” Ballantyne said.

While the industry has been apprised of the plan, DfT insiders said it had yet to be signed off officially.

Ports such as Dover, the main gateway to the EU, have been preparing for Brexit for three years and believe they are as ready as they can be.

But senior executives at ports have warned that if business or the government is not prepared enough for customs declarations and food and animal health checks on the other side of the Channel, there could be chaos at the border.

Earlier this year Portsmouth warned that parts of the M3 could be turned into a lorry park if it was to act as a relief port to Dover.

The port’s director said plans to use nearby land had been jettisoned because the owner, the Ministry of Defence, had refused to release it for no-deal use.

The BPA also warned that the ports were only one part of the Brexit jigsaw, and that other potential risks included lack of customs agents and government tax software systems.

Before being selected as the leader of the Conservative party, Boris Johnson also warned about the impact of lack of business preparedness, revealing that just 30% of businesses that export to the EU had applied for the economic operator and registration identification number needed in the event of no deal.