US banking giant JP Morgan has snapped up an office building in Dublin with the capacity to house 1000 staff as it ramps up its Brexit contingency planning.

The bank said earlier this month it planned to move up to 1000 London jobs to Dublin, Frankfurt and Luxembourg in a bid to secure its EU business after Brexit. Now it has acquired the 200 Capital Dock building in the Irish capital.

It is understood the expansion is also down to the success of its existing operation in the city, where it currently employs 500 people.

Carin Bryans, senior country officer for JP Morgan in Ireland, said: “Given the momentum of our local businesses, this new building gives us room to grow and some flexibility within the European Union.”

The chief executive of JP Morgan’s corporate and investment bank, Daniel Pinto said at the beginning of the month that a “substantial portion” of the lender’s business in London will have to be moved to the EU.

He said: “We will have to move hundreds of people in the short-term to be ready for day one, when negotiations finish, and then we will look at the longer-term numbers. We have to plan for a scenario where there is no UK-EU passporting deal, and we have to move a substantial portion of our business to continue serving our European clients,” he said.

JP Morgan will relocate between 500 and 1000 front and back office staff from London, with custody business roles destined for Dublin, treasury services set to settle in Luxembourg, and investment banking positions bound for Frankfurt.

It is understood that the relocation drive will take place ahead of spring 2019, when the two-year window for Brexit negotiations draws to a close, and the UK is expected to lose passporting rights for financial services. Mary Ricks, boss of property group Kennedy Wilson, added: “The Dublin occupier market is buoyant and we are in active and advanced dialogue with both Irish and international companies attracted to our visionary Capital Dock development and looking to base themselves in the heart of Dublin.”

A growing list of financial services firms have confirmed their relocation plans following the Brexit vote, with HSBC moving 1000 staff to France, AIG set to shift a string of executives to Luxembourg, and Lloyd’s of London opting for a subsidiary in Brussels.

JP Morgan chief executive Jamie Dimon previously indicated around 4000 of the bank’s 16,000 UK employee base could move as a result of Brexit.

Meanwhile, Jeremy Corbyn has indicated that he would agree to Britain paying a so-called Brexit “divorce bill” of money it legally owes the European Union if he wins power in the General Election. The Labour leader said the UK “must honour” its legal obligations on “long-term investment projects”, but that any other demands from the EU for money would be open to negotiation.

Corbyn refused to say if he would agree to the EU’s demands for the UK to settle its accounts before talks on a future trading relationship can begin, but said he would sit down with Brussels negotiators to agree a programme on “day one” of a Labour government.

Corbyn’s comments came after Brexit Secretary David Davis warned of a “row” with the EU over the sequen- cing of talks and Foreign Secretary Boris Johnson insisted the divorce bill, now potentially as high as €100 billion (£85bn), would only be agreed once everything, including future trade relations, was agreed.

Corbyn criticised the Tories’ “bellicose” approach to negotiations and said he was “really struggling with what David Davis’s strategy is – and Boris Johnson also, for that matter”.

Asked at the Royal College of Nursing conference in Liverpool if he would agree to an exit fee before beginning trade talks, he said: “Clearly where there are legal obligations on long-term investment projects both in this country and other places, they must be adhered to, we must honour them. The others, clearly, will be open to a negotiation and we would negotiate on that.”