Yes you can apply for car finance with a low income. As long as your monthly income totals £1,000 after tax (see what sources of income we accept).
If you are concerned that your monthly income might not quite be enough, you could always consider making a joint application for car finance. This means you can apply with either a spouse, partner, civil partner, son, daughter, or sibling. Both your names would be on the agreement and we would take both incomes into account. Both of your monthly incomes for a joint application must total £1,300 after tax.