Gujarat governor Kamla Beniwal, who had been at loggerheads with Modi over the issue of the appointment of a Lokayukta, will also be present.
Dr Singh and Modi will share the stage at a function to inaugurate a museum dedicated to Vallabhbhai Patel's life. The function has been organised by the Sardar Vallabhbhai Patel Memorial Society, whose chairman is the Union minister of state for mines, Dinsha Patel.
On Thursday, Modi would also lay the foundation stone of a 182-metre statue of the first home minister of the country, near the Sardar Sarovar Dam on the Narmada river.
As the 2014 Lok Sabha elections nears, both the BJP and the Congress have become vocal in criticising each other.
Modi has time and again targeted Singh and Congress vice-president Rahul Gandhi. During his election rallies, he has called Dr Singh as the most 'weak and helpless' prime minister in independent India's history.
On his part, Dr Singh has also been vocal against Modi recently. While returning from his US trip early this month, he had told reporters, "I sincerely hope that all secular forces would combine to face the onslaught of people like Narendra Modi. And I have every reason to believe that that will happen."
When Dinsha Patel was asked if he feared that Modi would criticise Dr Singh at the function, he said, "Good people will only speak good about others. How can I predict what Modi will say during the function. It is up to him what to speak."
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