The High Court has ruled that people with deep vein thrombosis (DVT) cannot sue airlines for their condition.

The judge said DVT should be classified as an accident under international legislation, but the DVT sufferers and their relatives who brought the case plan to appeal.

Clive Garner, partner at travel litigation specialists Irwin Mitchell solicitors, explains the impact of the ruling.

What action was brought to the High Court?

People are claiming damages for compensation against the airlines on the basis that they're responsible for causing DVT.

Several people have died as a result of DVT problems, with many have been left with serious injuries.

In terms of the compensation claims themselves, they are regulated by the Warsaw Convention, which is an international convention which deals with compensating people who have been injured on international flights.

The essence of the case is that people should be compensated under the terms of the convention, or indeed that the convention shouldn't be actually applied in cases like this.

Is this the end of the matter?

I'm not surprised by the ruling. The issue of DVT and airlines' liability for causing DVT is very complicated.

It's far from straightforward and there is, I think, a legitimate defence under the terms of the Warsaw Convention which regulates compensation for payments for people who have been injured during international flights.

Hopefully the claimants will succeed but there are very significant legal difficulties in winning their cases for them

It will be very surprising if it doesn't go through to an appeal and possibly a further appeal to reach the House of Lords. I'd be very surprised if it finished here.

It's an international problem and there's a web of legal decisions which will feed into it.

But I think it probably will go through to a further appeal and the result of that is very difficult to determine.

How would the High Court have come to a decision?

I haven't seen the decision as yet. I suspect that it will be on the basis of interpretation of the Warsaw Convention itself.

It is very old - it's a 1929 convention and the wording of it has been interpreted by the English courts and indeed courts around the world previously and there are tricky legal definitional points which are going to be critical to any decision.

The balance of those decisions so far has been that problems like DVT are unlikely to be compensated within the terms of the Warsaw Convention.

As far as compensation is concerned, the Warsaw Convention gives exclusive jurisdiction for compensation.

If you can't bring your claim within the Warsaw Convention, then you cannot recover compensation.

What does the ruling mean for passengers and airlines?

Bad news for passengers - for those that do develop DVT. It's going to be very, very difficult for them to actually claim compensation - certainly in the English courts.

There may be different decisions around the world in different courts.

At the moment all of the decisions that I've seen from different courts seem to go along with what the UK courts are saying in that compensation is unlikely to be recovered.

As far as the airlines are concerned, we know that they have been aware of the risks of DVT for some time

We know that the judge who actually considered this matter wants to hear what the courts in Australia have determined on the same point.

There are also cases around the world, in the United States and other courts, where there have been similar rulings on similar sorts of conditions.

As far as the airlines are concerned, we know that they have been aware of the risks of DVT for some time.

There has been research ongoing for many years and it's only very recently that they've taken steps to ensure that passengers are aware of the risks and taking steps to minimise the risk of DVT.