'What I have learned from Spanish devolution is that every day Spain demonstrates the success of the principles we hold dear,' he said during an address to the Future of Europe conference, organised by the British Council and the British embassy in Spain.
'In Spain, decentralisation and autonomy plans have been tailored to meet the needs of each individual region - nobody has suggested a one-size-fits-all plan as some have suggested should happen in the UK.
'The fundamental unity of the Spanish state has been preserved - proving that decentralisation does not necessarily lead to what we in the UK call the 'slippery slope to separation'.
'It is no wonder that - since the beginning of 1998, when we in the UK began seriously to look at the mechanics of devolution - Spain has been visited by so many senior politicians and government officials from Wales, Scotland and Northern Ireland.
'But I hope, as one of the 'new kids on the block' of decentralisation, that this will not just be a one way process and that we in the United Kingdom and indeed Wales can bring new insights and ideas too.'