Login - Bad Request: The CSRF token could not be verified

I have just deployed an existing site to a new server. As the DNS is not pointing there yet, I have simply edited my /etc/hosts file on my Mac to point to the IP address for testing. Whilst checking through everything, it seems the site is functioning well, assets have been copied over etc. The only problem is that I am getting an error when trying to log in.

From the front end I get the message: Bad Request: The CSRF token could not be verified.

    2017/07/17 13:52:33 [error] [exception.CraftHttpException.400] CraftHttpException: The CSRF token could not be verified. in /home/forge/www.domain.co.uk/craft/app/services/HttpRequestService.php:1337
Stack trace:
#0 /home/forge/www.domain.co.uk/craft/app/framework/base/CComponent.php(561): CraftHttpRequestService->validateCsrfToken(Object(CEvent))
#1 /home/forge/www.domain.co.uk/craft/app/framework/base/CApplication.php(212): CComponent->raiseEvent('onbeginrequest', Object(CEvent))
#2 /home/forge/www.domain.co.uk/craft/app/framework/base/CApplication.php(183): CApplication->onBeginRequest(Object(CEvent))
#3 /home/forge/www.domain.co.uk/craft/app/index.php(62): CApplication->run()
#4 /home/forge/www.domain.co.uk/public/index.php(19): require_once('/home/forge/www...')
#5 {main}
REQUEST_URI=/members/login
HTTP_REFERER=http://www.domain.co.uk/members/login
---

And from the craft admin login form, this comes up on the console after clicking Login

VM43:1 POST http://www.domain.co.uk/index.php?p=admin/actions/users/login 400 (Bad Request)

One point to note is that the original website was SSL encrypted but the new server hasn’t had an SSL cert installed yet, because DNS is not pointing to it yet. However I have altered the /craft/config/general.php config file to reflect the http:// domain.

Any help would be appreciated.
Running latest craft 2.6.2987