Electronic Credit Ledger blocking permitted only up to ITC actually available; negative balances and extra statutory recovery are impermissible.
Rule 86A may be invoked only where input tax credit is actually available in the Electronic Credit Ledger at the time of the blocking order; the power permits disallowing debit equivalent to such available credit as a temporary preventive measure and does not authorize creation of negative ledger balances or serve as a recovery provision. Excess blocking beyond the ECL balance is ultra vires and recovery must proceed under the Act's substantive provisions.