The Reserve Bank of New Zealand has issued a fresh consultation paper with even sharper view on "speed limits" for high loan-to-valuation ratio mortgage lending.The bank says it wants submissions by July 3 and wants banks to be sufficiently pre-positioned "so that LVR restrictions could be applied in the relatively near future." It says it wants to publish an updated version of its Banking Supervision handbook that includes such limits by mid-July.The RBNZ re-stated that it wants to be able to impose the restrictions with a notice period of as little as two weeks. The bank said it had made no final decision about imposing the speed limits, but it has argued repeatedly this year that it needs this macro-prudential tool, and others, to try and reduce the risks of a housing slump because of what this would for bank stability. The central bank is also trying to slow down riskier mortgage lending growth without damaging the rest of the economy by hiking up the official cash rate.It also reiterated that it wanted to use a "speed limit" approach that would limit the shares of new high LVR lending that a bank might undertake. The limits would be imposed through the conditions of bank registration.Elsewhere in the paper, the bank said its "Stage 2" review of bank capital adequacy requirements for mortgage lending was likely to result in changes to the definitions of the loan amount and loan value, as well as what constitutes a credit event. It expects to finalise these changes by mid-July.The bank said the speed limits would be expressed cumulatively rather than in separate bands. It said, for example, that the limits might state that no more than five per cent of new lending may have LVRs of over 90 per cent, and no more than 10 per cent of new lending may have LVRs of over 80 per cent. They could also be tiered in five per cent increments from 60 per cent to 100 per cent.If these were the limits imposed then ANZ, CBA's ASB and NAB's BNZ would have to significantly reduce their lending growth in high LVR lending. Interest.co.nz figures show about 30 per cent of ANZ's new lending in the March quarter was in mortgages with LVRs of over 80 per cent, while ASB's high LVR share of new lending was 71 per cent, and BNZ's was 35 per cent. Westpac's share was eight per cent and Kiwibank's was five per cent.The central bank also specified possible exemptions to the speed limits, including Welcome Home loans administered by Housing New Zealand that are designed to tempt home returning ex-pats who have low deposits but high incomes. It also said existing high LVR loans being rolled over on new terms would not qualify under the speed limits. Bridging loans would also be exempt.The bank said it would also move to stop "top up" loans, where banks wrote second mortgages for the same customers on the same asset so as to get around