From guardian “The wave of strikes was triggered last week when contractors in Lincolnshire protested outside Total's Lindsey refinery, in North Killingholme, at the decision to give up to 300 jobs to European workers.”
What does this mean?
It means that workers are fighting against each other because of a long lasting economic crisis and consequent high unemployment rate.
For the Owners (therefore for the capitalist system) labour-power is labour-power it does not have nationality. What does make a difference is its price on the labour market.
"Labour has a Price, and that, the price of a commodity being only the monetary expression of its value, there must certainly exist such a thing as the value of labour. However, there exists no such thing as the value of labour in the common acceptance of the word."
"Like that of every other commodity… value of labouring power… is determined by the quantity of labour necessary to produce it. The labouring power of a man exists only in his living individuality.
A certain mass of necessaries must be consumed by a man to grow up and maintain his life. But the man, like the machine, will wear out, and must be replaced by another man.
Beside the mass of necessaries required for his own maintenance, he wants another amount of necessaries to bring up a certain quota of children that are to replace him on the labour market and to perpetuate the race of labourers.
Moreover, to develop his labouring power, and acquire a given skill, another amount of values must be spent" (Marx, Value, Price and Profit, 1865).
The difference can be made by welfare of the labourer which might differ for different countries (or better, markets).
Since the Owner goes always for the cheapest labour-power, he/she would either move his/her enterprise to a country where the wages he/she has to pay are lower or he/she would give a job to who, without any alternative, would work for a low wage in his/her own country.
We have a clear example of this phenomenon. The high number of companies moving to the East Europe/Asia or as in Manchester companies underpaying workers.
Nationalism will not solve the economic crisis. Conversely, union of the workers all over the world can change the economic system.