london investors lend billions euros spain every year struggle sketch repercussions country finance possible independence proclamation wealthy region catalonia regional leader carles puigdemont prepare address tuesday parliamentary session may unilaterally declare independence spain follow ban referendum oct. 1. move would drive wedge spanish government region make fifth country economic output quarter export one fund manager tell reuters work pan euro zone fourth large economy complicate make brexit look like walk park best guess far scenario consider unlikely many analysts could prove damage spain overall financial position economy government borrow cost secession would also expect harm catalonia economy uncertainty likely push bond yield newly-independent state well spain accord abn amro catalan independence could raise spain government-debt ratio high 115 percent gdp current level around 99 percent leapfrog cyprus belgium fourth large debt load euro area however catalonia say would take responsibility share central government debt reduce burden spain real problem would spain would balance book without catalonia contribution roughly 4.5 percent gdp 2016 spain already high budget deficit euro zone fathom consult say catalonia leave economic shock could see budget deficit run nearly percent couple years back level see wake euro zone debt crisis abn amro forecast deficit 5.5-6 percent many analysts expect likely outcome spain bad political crisis decades great devolution power catalonia like enjoy basque country generous fiscal autonomy madrid could come considerable cost public purse accord 2014 study research house csic spanish state could lose 16 billion euros would equal 13 percent next year budget would painful economically say tim davis chief investment strategist fathom consult budget deficit spain would increase would need see kind additional austerity plug gap would start see bond yield rise seem outcome leave spain economy unscathed rat agencies already say tensions alone could negative consequences spain credit rank deter investment weaken ability spain minority popular party government implement national policy crisis already look claim first victim delay pass 2018 budget tensions increase catalonia defy madrid declare independence come days one tool spain disposal trigger article 155 constitution would allow take control devolve power story refiled remove erroneous word paragraph spain 's creditors size cost catalan independence bid