By Corina PonsMADRID, June 29 (Reuters) - Several non-governmental organisations in Spain are urging undocumented migrants to register in a final push for a special mass regularisation process that has attracted around a million people in just a few weeks and is set to end on Tuesday.

El martes acaba el plazo de la regularización, un tiempo insuficiente para sus impulsores

It's a race against time in Spain, where undocumented migrants have just hours left to apply for a special mass regularisation programme before the deadline expires.