Magic circle firms Clifford Chance and Linklaters have set up 24-hour operations rooms in preparation for the fallout from UK's referendum on membership of the European Union (EU) this Thursday.

The pair are preparing for an avalanche of enquiries from clients, especially in the event of a vote in favour of Brexit, about what the result will mean for their businesses.

CC's "24-hour rapid response unit" will open when voting begins this week on 23 June.

Led out of London, it will include a team of lawyers and staff across the firm's offices in major financial centres in Europe, Asia Pacific and the Americas.

CC senior partner Malcolm Sweeting said: "We have been working on the likely implications of a Leave vote for several years now and have established a dedicated 24-hour rapid response unit. The facility will be staffed from the opening of the polls for as long as necessary to ensure we can quickly and effectively respond to the needs of our clients, wherever they are based."

We have been working on the likely implications of a Leave vote for several years now

The team will include the firm's London managing partner David Bickerton, alongside financial regulatory head Chris Bates, London head of finance Michael Bates and head of employment Chris Goodwill, as well as associates and support staff. 

They will also have a staffed hotline and dedicated email address to manage incoming queries. In the event of a Brexit result, the contact details will be on the firm's homepage.

Meanwhile, Linklaters' executive committee and partnership board will be convening Friday morning to provide senior leadership guidance. In addition, the firm will have partners on standby overnight to advise clients on any immediate queries.

The firm's core "referendum steering group", established in early 2015, will be operating out of a central hub.

Other top UK firms are also putting plans in place to serve clients during the referendum.

Herbert Smith Freehills (HSF) has had a small EU exit working group since March 2015, led by head of legal knowledge Simone Pearlman (pictured right) corporate partner Gavin Williams and consultant Dorothy Livingston.

It has a dedicated taskforce of around 40 people who will be available to clients from 6:30am Friday morning.

Pearlman says that at the beginning of 2016, "Clients came flocking as they woke up to the fact that there was a possibility of leaving EU, and could their lawyers help?"

Clients came flocking as they woke up to the fact that there was a possibility of leaving EU

Lawyers at the firm has also joined the rush of lawyers opting apply to join the roll of solicitors in the Republic of Ireland, in the hope they would retain their European Court of Justice appearance rights if the Brexit camp prevails on 23 June.

Other firms that have already done this include Slaughter and May, Freshfields Bruckhaus Deringer and Allen & Overy.

"We do have a number of lawyers that have been admitted in Ireland in the last few months as a response to the possibility of Brexit. It's currently less than 10 but this number could rise," said Pearlman.

Meanwhile, Nabarro has a Brexit contingency group run by City corporate partner Alasdair Steele (pictured left). It comprises 15-20 partners across London, Sheffield, Manchester and Brussels. The group came together in February this year.

Steele said: "It covers all the disciplines in the firm. It will be down to the partners to get in contact with their clients. They will be getting in touch with them on a one-to-one, bespoke basis next week and the week after." 

Since acting for News Corporation on the phone hacking scandal, Olswang has had a crisis management task force in place alongside a "special situations" group set up since the financial recession.

Coordinating the special situations team to field any questions related to the referendum is City finance partner Alicia Videon.

If we vote out, there will be quite an extreme period of uncertainty. We've been having conversations with clients on practical contingency plans 

She said: "If we vote out, there will be quite an extreme period of uncertainty. We've been having conversations with clients on practical contingency plans around key areas of risks such as currency shock and asset classes."

Simmons & Simmons also set up a task force earlier this year to handle similar queries. The 20-strong partner group is run by head of corporate Mark Curtis in London.

In the run up to the vote, he said that there has been "a lot of interest and concern" from clients in financial services as well as other sectors like data protection, employment, IP and tax.

Yesterday, Dechert unveiled it was setting up a hotline from its London office to field queries on the implications of the Brexit vote.