Extending its sharp slide from late May high level of 163.89, the GBP/JPY pair on Monday plummeted to its lowest level since August 2013 before retracing a bit, to currently trade around 150.00 psychological mark.Earlier on Monday, the pair resumed its Friday's late slide led by the latest EU referendum poll outcome that intensified fears of a potential 'Brexit' and its negative implication on the UK economy. Friday's ORB polls showed 55% voters favored 'Leave' camp as against 45% supporting to remain in the EU. Following the release of the poll results, the GBP/JPY cross slammed to 151.50 before settling at its lowest level since August 2013.Monday's slide for the GBP/JPY cross was triggered by a fresh polls from Opinium that revealed huge support for a 'Brexit'. Adding to it global risk-aversion led to a fresh bout of buying interest for the perceived safe-haven currency, Yen, exerted additional pressure on the GBP/JPY cross.Moving forward, investors will focus on Tuesday's CPI release from the UK ahead of the key monetary policy decision from the Bank of Japan on Thursday, which are likely to determine the near/medium-term direction for the pair.Technical levels to watchOn the immediate downside, 149.00 round figure mark seems to extend immediate support, below which the pair seems to continue drifting lower towards its next major support near 147.50, with intermediate round figure mark support around 148.00 level. On the flip side, sustained recovery momentum above 150.00 mark is likely to boost the cross back towards 151.00 handle resistance ahead of a key support break, now turned strong resistance near 151.50-70 region.