BRUS­SELS-Eu­rope's lead­ers gath­er in Brus­sels un­der mount­ing pres­sure to soft­en their tough-love ap­proach to the weak­er economies among them. With Greece locked in po­lit­i­cal chaos, much big­ger Spain warns it can't keep afloat with­out help, as stock mar­kets around the world tank over fears the lead­ers won't have the po­lit­i­cal will to act.

The sum­mit will have to fight mul­ti­ple fires: po­lit­i­cal un­cer­tain­ty in Greece that could see it re­nege on com­mit­ments made to se­cure res­cue loans; ris­ing bor­row­ing costs in Spain and Italy that could force them to seek bailouts; and slug­gish growth across the re­gion ex­ac­er­bat­ed by bud­get cuts meant to re­as­sure mar­kets about high debt lev­els.

"What we need is a de­ci­sive plan for Greece, and we need de­ci­sive plans to help get the Eu­ro­pean economies mov­ing," British Prime Min­is­ter David Cameron said as he head­ed in­to the sum­mit of lead­ers of the 27 coun­tries that make up the EU, which in­cludes the 17-mem­ber eu­ro­zone.

"But if we're not go­ing to keep com­ing back and back to meet­ings like this we al­so need to deal with some of the longer-term is­sues at the heart of run­ning suc­cess­ful sin­gle cur­ren­cy, hav­ing a bank that gets be­hind that sin­gle cur­ren­cy, hav­ing co­her­ent long-term plans to make sure that sin­gle cur­ren­cy is co­her­ent," he said.

Lead­ers have said that every­thing will be on the ta­ble, in­clud­ing a dis­cus­sion about whether the coun­tries that use the eu­ro should spread the risk and bor­row mon­ey joint­ly-is­su­ing so-called "eu­robonds." This would mean every coun­try could bor­row funds at the same rate, sub­stan­tial­ly low­er­ing the costs for the more in­debt­ed coun­tries.

But ex­pec­ta­tions were low for agree­ment on con­crete mea­sures to boost growth and sta­bil­i­ty in the eu­ro­zone. Eu­rope's main stock in­dex­es plunged more than 2 per cent. The eu­ro fell 0.8 per cent to US$1.2561, its low­est in near­ly two years.

On Tues­day, the Or­gan­i­sa­tion for Eco­nom­ic Co­op­er­a­tion and De­vel­op­ment be­came the lat­est body to warn that the eu­ro­zone is at risk of falling in­to a "se­vere re­ces­sion" and sug­gest that it slow the pace of aus­ter­i­ty, or cost-cut­ting mea­sures, in some coun­tries.

That's ex­act­ly what many in Greece are ask­ing for. The coun­try has un­der­tak­en mas­sive spend­ing cuts and tax hikes to slash its deficit and rein in its debt-and in ex­change for the bailout loans that help keep it pay­ing the bills.