In Britain, legal costs are extremely high and your access to the law, is for many people, dependent on your ability to pay. There are many actions that as an individual, unless very wealthy or having backers, you are unable to take, for example libel. I talked to a solicitor approaching 20 years ago about a libel action I was considering and at that time I was told that I had to have half a million pounds to put on the table to play this game.
Within civil actions the persons ability to pay eventually, may also effect the initial stages of some types of actions, for example if a large company tries to take out an injunction against you to stop you using a word in the English language, they will be unlikely to eventually succeed, but they will get their initial injunction until a full hearing, simply because if they loose they can afford to pay the damages and should you loose, you would not. In practice they would soon be looking for a way out. This is from my own experience when I defended an action myself in the High Court on the use of a word within a company name, at. It cost them around £8,000 in legal fees plus court costs, and me just my train fare. We ended up with a draw, as by the time the action started I had renamed the company, but they still wanted to prove their point, but eventually also wanted to call a draw after the judge warned them that large damages would be flowing in my direction should they loose.
If you are using a solicitor and eventually a barrister, they are going to be really keen to make sure that there very high fees can be paid. Or that arrangement exist covering this.
Ultimately if using solicitors there are three ways of funding a case
If you are not using a solicitor and lose you could end up having to pay the costs of the other side in full. You are extremely unlikely to be able to get insurance if handling the case yourself.
You also have to fund court costs, and expert report fees etc. Some reduction or exemptions may apply to court fees - see references below.
The court service page of leaflets and forms relating to fees is at http://www.courtservice.gov.uk/fandl/menu_fees.htm
EX 50 gives the current fee structure
Leaflet EX160A relates to who has to pay them and form EX160 is used for asking for exemption or remission, currently the download for these is not working on the site
Other information is also available, from the same point.