JUDGMENT

Raja Azlan Shah CJ (Malaya) (delivering the judgment of the Court):

The appellants orally agreed to allow the respondents to occupy their premises for so long as they wished on payment of tea-money. Two written agreements were later executed, but did not refer to the appellants' promise. Sections 91 and 92 of the Evidence Act state that extrinsic evidence is not admissible to vary, add to or contradict the terms of a written agreement. Can the respondents enforce the promise in the light of the two sections of the Evidence Act? The learned Judge answered in the affirmative. That sums up the question raised in the instant appeal.

The facts are as follows: In 1957 the respondents were looking for premises in Kluang, Johore, to carry on the business of an eating shop. They found one at No. 11, Jalan Dato Teoh Siew Khor belonging to the appellants. But the premises was not suitable for their purpose as it was designed as a bank. Negotiation commenced with the appellants. The appellants wanted $14,000 teamoney to allow the respondents to occupy the premises. A reduction in the amount of tea-money was offered but rejected. As a result an oral agreement was reached between the parties whereby the respondents were to rent the said premises on payment of $14,000 tea-money and they could stay there for as long as they wished provided they paid rent regularly. Relying on that oral assurance the respondents went into occupation. They paid the tea-money and received the first month's receipt at the back of which were recited seven conditions, viz: no sub-letting without the appellants' consent, no contraband goods to be stored in the premises, notice by the respondents to appellants on termination of tenancy, prohibition against cutting of firewood within the premises, payment of local council fees, premises to be kept clean and tidy and lastly, appellants' right to terminate tenancy on failure to observe any one of the above conditions. No receipt was given in respect of the tea-money. That we think is obvious. With the consent of the appellants, they expended substantial sum of money to make the necessary alterations to the said premises so that it was fit to be used as an eating shop.

In 1961, the parties entered into a written agreement whereby the rent was increased from $200 to $220 per month. No mention was made of the earlier oral assurance.

In 1967 another written agreement was executed increasing the rent from $220 to $254 per month. It is in substance the same as the previous written agreement except one, that is cl 7 which is in the following terms:

In the event of any increase in the Town Council assessment, quit rent and other taxes relevant to the premises the rental shall be increased proportionately in accordance with the increase levied by the Government or the Authorities.

At the end of 1968 there was a dispute regarding payment of rent. The appellants demanded an increase of $10 rent in view of the increase in assessment. The respondents did not agree to the increase. They pointed out that as the assessment had only been increased from $349.70 in 1968 to $403.50 in 1969, they said they would be willing to pay the difference, that is, $53.80 per annum, which is equivalent to $4.50 per month. The appellants referred the respondents to cl 7 of the agreement and argued that nowhere was it stated that the rent was to be increased in the same proportion as the increase levied by the Government. They accordingly interpreted it as enabling them to increase rent twice or even ten times. There was exchange of correspondence. In December 1969 the appellants wrote to the respondents suggesting an amicable settlement on payment of increase of rent in the sum of $55 per month. They wrote again at the end of the month offering a tenancy of ten years instead of 20 years. In February 1970, they gave the respondents notice to quit by end of March 1970. The respondents did not do so. They paid rent for February and March 197